The right word, plainly stated, no translated jargon.

Gap between actual and target allocation, which widens over time as outperforming classes gain weight. Past a threshold (typically 5 points), you rebalance.

Annual Social Security ceiling: a reference amount revalued each year (€48,060 in 2026) used to compute many caps — contributions, but also employer matching and employee-savings bonuses.

Algemene Ouderdomswet: the Dutch state pension, flat-rate and pay-as-you-go — the 1st pillar, on top of which sits the huge funded occupational 2nd pillar.

Average revenue per user (or subscriber) over a period. A decline can reflect expansion into cheaper markets as much as a slowdown — read it alongside subscriber growth.

A widely-used French savings and investment wrapper. Allows investing in euro-denominated capital-guaranteed funds and/or unit-linked (stocks, bonds, real estate). Tax-advantaged after 8 years.

Old-age and survivors’ insurance: Switzerland’s public 1st pillar, pay-as-you-go. The base of the three-pillar system, completed by occupational provision (LPP) and private savings.

Market in a sustained downtrend. The conventional threshold is -20% from the last peak, but the term mainly applies to longer, deeper drops (-50% to -90% in crypto, where bear markets can last 1 to 2 years). Opposed to bull market (uptrend). The animal analogy: the bear strikes downward, the bull gores upward.

Standardized document proposing a change to the Bitcoin protocol, wallet format, or application convention. Each BIP has a number (BIP-32 HD derivation, BIP-39 mnemonic phrase, BIP-141 SegWit, BIP-340/341/342 Taproot, BIP-350 bech32m…). Inspired by Python PEPs; the process is public on GitHub.

The first decentralized crypto-asset, created in 2009 by Satoshi Nakamoto. Runs on its own blockchain.

Cryptocurrency that emerged from a hard-fork of Bitcoin in August 2017, initiated by part of the community that wanted larger blocks (8 MB then 32 MB) to process more on-chain transactions. From block 478,558 onward, two chains coexist: BTC (which follows the SegWit, then Lightning and Taproot roadmap) and BCH (which bets on on-chain scaling). BCH itself spawned Bitcoin SV in 2018 (another fork).

An alternative Bitcoin node implementation maintained by Luke Dashjr, derived from Bitcoin Core but with stricter relay policies (notably filtering of non-financial data). It is the software that ships BIP-110 support, at the heart of the “Core versus Knots” rivalry.

A digital ledger shared across many computers, where transactions are grouped into cryptographically-linked blocks. Practically tamper-proof.

The US Bureau of Labor Statistics. Publishes the US CPI and the monthly employment report (NFP).

Capital expenditures: money spent to acquire or improve long-lived assets (factories, satellites, datacenters). Capex above the cash generated by operations must be funded with debt or share issuance.

The gain realised when an asset is sold: the difference between sale price and purchase price. It is the gain (not your original capital) that is taxed — at the 31.4% flat tax on a brokerage account, or under each wrapper’s own rules.

Time-savings account: a company device for banking unused days (RTT, leave) and, depending on the agreement, some amounts. These rights can be cashed out, transferred to a PER (up to 10 days/year free of income tax) or fund an end-of-career leave to retire earlier.

A split of the blockchain into two distinct chains when part of the network enforces rules incompatible with the rest. Each chain then continues its own history and becomes a different coin — as when Bitcoin Cash was born in 2017. It is the risk raised against any contested activation of a consensus change.

A systematic distortion in judgment, identified by behavioral psychology (anchoring, loss aversion, confirmation bias, recency, FOMO…). You don’t get rid of them — you protect yourself from them, typically with a written method.

Wallet whose keys are stored offline (typically a dedicated device — a hardware wallet). Much safer for savings.

Collective company retirement plan (PERECO, formerly PERCO): an optional workplace retirement plan, fed by employee savings, voluntary payments and matching; locked until retirement (barring main-home purchase and life accidents).

A mandatory pension that adds to the base scheme. For private-sector employees it is Agirc-Arrco, run on a points basis: contributions buy points, converted into a pension at retirement. It is still pay-as-you-go.

Process by which interest (or gains) from one period is reinvested and itself earns interest in the next. Over the long run the effect is exponential: capital returning 7%/yr roughly doubles every 10 years, with no further contributions.

The unit used to count contribution length. The number of validated quarters (not just calendar quarters worked) determines entitlement to a full-rate pension. A quarter is earned through a threshold of contributed income, not solely by time spent.

France’s Pensions Advisory Council: an independent public body that analyses and projects the financial balance of the French pension system. Its annual reports are the shared numerical reference in reform debates.

Consumer Price Index. Monthly measure of the average change in price of a basket of goods and services. The headline “inflation” figure, published by INSEE in France, Eurostat in the eurozone, and the BLS in the US.

France’s standard taxable brokerage account: no cap, access to all global markets, but a flat tax of 31.4% (2026) on gains and dividends with no allowance. The default wrapper, useful once you’ve maxed out PEA and AV — typically for non-EU stocks, derivatives, listed real estate, etc.

Investment strategy of buying a fixed amount on a regular schedule, regardless of price. Smooths the entry price.

Decline in shareholders’ ownership stake (and often per-share value) when new shares are issued. In an IPO, it also measures the gap between the price paid and the net tangible book value per share.

Capital split into several share classes with unequal voting rights (e.g. Class B shares carrying 10 votes, reserved for founders). It lets a company raise money while keeping control: the public can hold a large share of capital for a minority of votes.

Earnings before interest, taxes, depreciation and amortization. Approximates operating profitability before financing and accounting choices. Adjusted EBITDA further strips out costs deemed ’non-recurring’ (stock-based compensation, restructuring…) — so it can flatter a capital-intensive segment. Always compare it to operating income.

European Central Bank. Sets eurozone policy rates and steers monetary policy. Its US counterpart is the Federal Reserve (Fed).

Elliptic-curve digital signature scheme, standardized by NIST in 2000. Bitcoin’s original signature scheme since 2009. Its security relies on the hardness of the elliptic-curve discrete logarithm problem (ECDLP). Achilles heel: the signature nonce must be absolutely secret and unique.

The set of schemes through which a company shares its results with employees and helps them save: profit-sharing, statutory profit-sharing and employer matching, held in a PEE or a company PER — with tax and social advantages.

An extra employer contribution added to what the employee puts into their plan. Capped (on a PEE: 3× the employee’s payment and 8% of the PASS; more on a company PER). “Free” money for the employee.

Exchange-traded fund that tracks an index (S&P 500, MSCI World, etc.). Fees often under 0.5%/year. The go-to tool for broad market exposure without picking individual stocks.

Statistical office of the European Union. Aggregates and harmonizes member-state data — the source for eurozone CPI.

The US central bank. Its rate decisions have global impact well beyond the dollar — in practice, it sets the world’s reference cost of capital.

Norway’s national insurance: the public scheme that actually pays current pensions, pay-as-you-go — not to be confused with the sovereign fund (GPFG).

The urge to chase an opportunity you fear missing. Drives buying late, at peaks, out of herd behavior. The single most expensive cognitive bias for a retail investor — it buys what a written method would skip.

A capital-guaranteed life-insurance vehicle: the insurer guarantees the amounts paid in plus interest already credited (ratchet effect). Mostly invested in bonds. Safety and liquidity at the cost of modest returns. The counterpart to unit-linked supports, which carry no guarantee.

Cash generated by operations once capex is paid (operating cash flow − investments). When negative, it signals the company relies on external funding to sustain its investment pace.

Crypto exchange founded by Sam Bankman-Fried in 2019, which grew into the world’s 2nd or 3rd largest before collapsing in November 2022. The bankruptcy revealed that customer funds had been diverted to Alameda Research, SBF’s sister fund, to cover losing bets. SBF was convicted of fraud in November 2023 and sentenced to 25 years in prison. The second major textbook case of centralized custody risk, after Mt. Gox.

A system where each person (or their employer) saves and invests to fund their own future pension; the accumulated capital is exposed to markets. In France it is marginal and mostly optional (PER, workplace retirement savings), sitting above the mandatory pay-as-you-go base.

The first block of the Bitcoin blockchain, mined by Satoshi Nakamoto on January 3, 2009. Numbered 0, it contains a famous message in its coinbase field: “The Times 03/Jan/2009 Chancellor on brink of second bailout for banks” — a reference to a Times headline from that same day, which serves both as a date proof (impossible to have mined earlier) and a political wink. The 50 BTC reward is deliberately unspendable (a software choice by Satoshi, never documented).

Government Pension Fund Global: Norway’s sovereign fund, the world’s largest (~$1.7tn), fed by oil revenues. Despite its name, it does not pay current pensions: it tops up the State budget via a ~3%/year rule.

A transition rule that applies a reform only to new entrants, leaving those already in place under the old rules. When used to close a special scheme, it fades out slowly, over decades, as its last members retire.

The halving of Bitcoin’s miner reward, which occurs every 210,000 blocks (roughly every 4 years). Reduces the flow of new bitcoins.

Non-backward-compatible Bitcoin protocol change: the new rules are incompatible with the old ones, so non-upgraded nodes reject the new blocks and the chain splits in two. Opposed to a soft-fork (backward-compatible change). Bitcoin has had no major consensus hard-fork since 2009; famous forks (Bitcoin Cash 2017, Bitcoin SV 2018) created new cryptocurrencies, they did not modify Bitcoin.

Bitcoin slang born in December 2013 on the BitcoinTalk forum, after the viral “I AM HODLING” post by user GameKyuubi — a deliberate misspelling of holding, written during a market crash. Refers to the strategy of keeping one’s bitcoins long-term despite volatility, as opposed to active trading. Backronymed as “Hold On for Dear Life”.

Internet-connected wallet (mobile, desktop). Convenient but more exposed. Fine for small amounts.

A technique that appeared in early 2023 (Casey Rodarmor’s Ordinals protocol) inscribing arbitrary data — images, text, BRC-20 “tokens” — directly into the witness part of Taproot transactions, attaching it to individual satoshis. It is the origin of the wave of non-financial data on Bitcoin that BIP-110 seeks to limit.

France’s national statistics office. Publishes CPI, unemployment, GDP and other macro figures.

Anomaly where short-term rates (e.g. 2-year) exceed long-term rates (e.g. 10-year). Has preceded almost every recent US recession — hence its status as a leading indicator.

Initial Public Offering: the first sale of a company’s shares on a public market, taking it from private to listed. Governed by a prospectus filed with the regulator (the SEC in the United States).

Individual Retirement Account: an American individual retirement savings account, funded and with tax advantages. The individual counterpart of the 401(k) — the equivalent, on the personal side, of a French PER.

Identity verification process required of regulated platforms. Includes government ID and proof of address.

Layer 2 payment protocol built on top of Bitcoin, operational since 2018. Enables near-instant, near-free transactions between two parties via payment channels that touch the Bitcoin blockchain only at opening and closing. Designed for everyday payments (a coffee, a tip), where layer 1 is more suited to larger settlements. Total network capacity: several thousand BTC by 2026.

French state-regulated savings account with a government-set rate, capped at €22,950. Capital guaranteed, tax-free, fully liquid. A precautionary tool, not a long-term investment — its rate rarely keeps pace with inflation.

Period during which certain shareholders (founders, employees, pre-IPO investors) cannot sell their shares after the listing. When it expires, a wave of stock becomes sellable — potential selling pressure on the price.

A 2016 French law whose article 49 lets the financial-stability board (HCSF) temporarily freeze withdrawals on life-insurance contracts in the event of a serious threat to financial stability. Capped at 6 months, never used to date, and limited to French-law insurers. Often raised as a watch-point versus Luxembourg life insurance, which is not subject to it.

Occupational pensions act: Switzerland’s 2nd pillar, funded and mandatory. Each employee builds up retirement capital there, on top of the AVS.

Investing a sum all at once, as opposed to DCA (regular spreading). Statistically beats DCA roughly two times out of three — but exposes you to bad timing, which few beginners can stomach emotionally.

“Broad money” monetary aggregate: cash + checkable deposits + short-term savings. When M2 grows fast, lots of money is chasing investments; when it stalls or shrinks, liquidity is contracting.

A historical Bitcoin flaw: until SegWit (2017), a signature could be re-encoded without becoming invalid and without knowing the private key, changing a transaction’s txid in flight without changing its effect. No theft was possible, but the identifier was unreliable — which prevented pre-signing transactions that reference unconfirmed ones, and therefore prevented building the Lightning Network.

Mandatory company retirement plan (PERO, formerly “article 83”): a plan set up by the employer for a category of staff, with mandatory contributions (employer and/or employee). It is the device found, for example, in the energy utilities (IEG).

Total value of a company on the market = share price × number of shares outstanding. Not to be confused with enterprise value (which adds net debt).

Total amount of money in circulation in an economy. Broken into aggregates (M0, M1, M2, M3) by liquidity. When it grows fast, almost everything rises; when it contracts, almost everything falls.

Japanese Bitcoin exchange launched in 2010, which handled up to 70% of global volume at its peak (2013-2014). It went bankrupt in February 2014 after ~850,000 BTC (customer + company funds) disappeared, following prolonged hacks exploiting a flaw known internally but uncorrected. A textbook case of centralized custody risk: “not your keys, not your coins”. Partial creditor reimbursements began in 2024.

A way to describe a pension organised in complementary tiers: a mandatory public pillar (often pay-as-you-go), an occupational pillar (often funded) and an individual savings pillar. Switzerland and the Netherlands frame theirs explicitly this way.

Drop in a stock’s valuation multiple (P/E, price-to-sales) without any deterioration in fundamentals. Typically triggered by rising long-term rates: the present value of future earnings mechanically falls.

Monthly US employment report (excluding farming), released by the BLS on the first Friday of each month. One of the most-watched figures globally — it can move equity, bond and FX markets within minutes.

Headline return, not adjusted for inflation. Almost always what financial products advertise. A 5% nominal return with 3% inflation translates to roughly 2% real.

Number used once. An arbitrary number used a single time in a cryptographic operation. Two distinct uses in Bitcoin: (1) the block header nonce, varied by miners to change the hash until it falls under the target (proof of work); (2) the ECDSA/Schnorr signature nonce, which must remain secret and unique — leaking or reusing it exposes the private key.

A Bitcoin script instruction that makes an output deliberately unspendable while letting you attach a small arbitrary data payload. It is the “clean” way to timestamp or anchor data without bloating the set of spendable outputs (UTXOs). The default relayed size was capped at ~80 bytes; Bitcoin Core v30 (October 2025) raised that cap to 100,000 bytes, triggering the controversy.

An instruction of the Script language, written OP_…. The most common ones: OP_DUP (duplicates the top of the stack), OP_HASH160 (hashes the top), OP_EQUALVERIFY (compares and fails if different), OP_CHECKSIG (checks a signature), OP_RETURN (makes the output unspendable). Some of the original opcodes, including OP_CAT, were disabled in 2010 and make any script invoking them fail.

Pay to Public Key Hash: the original output family (2009). The whole lock is written in the output — OP_DUP OP_HASH160 <hash> OP_EQUALVERIFY OP_CHECKSIG — and addresses start with 1. Still valid, but the most fee-expensive of the four families.

Pay to Script Hash (BIP16 , 2012): the output holds only the fingerprint of a script, revealed at spending time (the redeem script). Consequence: the payer needs to know nothing of the contract’s complexity — sending to a 2-of-3 multisig is as simple as sending to a normal address. Addresses start with 3.

Pay to Taproot (BIP341 , 2021): the output is OP_1 <32-byte public key>, a “tweaked” key encoding both a plain-signature spend and, hidden inside, a tree of alternative scripts. Addresses bc1p…. Not systematically cheaper than a P2WPKH output: Taproot mainly wins on multisig and consolidations.

Pay to Witness Public Key Hash: the “plain” SegWit v0 output (2017). Its lock is just OP_0 <20-byte hash>, with the signature moving into the witness. Addresses bc1q…, bech32-encoded. It is today the cheapest format for an ordinary one-input, two-output payment.

A system where contributions levied on today’s workers immediately fund today’s retirees’ pensions — no individual pot, but solidarity between generations. Its balance depends on the ratio of contributors to pensioners. It is the backbone of the French system.

A levy on wages funding social protection — the US equivalent of social-security contributions. The Social Security one is 12.4%, split between employer and employee.

French equity savings plan, limited to European stocks. €150,000 cap. Capital gains exempt from income tax after 5 years (social contributions still apply). FR-only concept, no direct equivalent abroad.

A PEA variant dedicated to financing European small- and mid-caps (equities, but also bonds and eligible crowdfunding instruments). Same tax perks as the PEA (income-tax exemption after 5 years, social contributions still apply). A €225,000 cap, but shared with the PEA: the two combined cannot exceed €225,000.

Company savings plan: an employee-savings wrapper that receives profit-sharing, voluntary payments and employer matching, invested in securities. Funds locked for 5 years (barring early-release cases).

Adjustments to the pension based on contribution length. A discount cuts it when quarters are missing at retirement; a premium raises it for quarters worked beyond the full rate. Two sides of the same lever: discouraging leaving too early, or with gaps.

French retirement savings wrapper. Contributions are deductible from taxable income (up to an annual cap), cutting your tax the very year you pay in — the higher your marginal tax bracket, the bigger the break. In return, the money is locked until retirement (barring specific early-release cases) and taxed on the way out.

Default tax regime for investment income (capital gains, dividends, interest), nicknamed the « flat tax ». A single 31.4% rate in 2026, split into 12.8% income tax and 18.6% social contributions. You may opt instead for the progressive income-tax scale if it works out cheaper.

Monthly index built from surveys of corporate purchasing managers. Above 50 = expansion, below = contraction. A leading indicator: it moves before official GDP figures.

The interest rate set by a central bank (ECB, Fed) at which it lends to commercial banks. The “zero point” of the whole chain: it propagates downstream into savings rates, mortgages, bonds and — indirectly — equity valuations.

Offering where the company issues new shares: the money raised goes to the company. By contrast, a secondary offering has existing shareholders sell their stock — the money goes to them, not the company.

An optional collective bonus tied to company performance. Exempt from income tax if paid into an employee-savings plan (PEE/PER), up to 75% of the PASS per year.

Legal document a company files with the regulator before going public. It describes the business, financials, ownership, use of proceeds and risk factors. It is the reference source for analyzing an IPO.

French regulatory registration required to offer crypto services. The French equivalent of the US BitLicense or UK FCA registration.

Inflation-adjusted return, measuring actual change in purchasing power. The only number that matters for a long-term investor: compounding at 5% nominal in a 5%-inflation economy is just treading water.

Bringing an allocation back to its target percentages by selling what’s grown above target and buying what’s drifted below. Mechanically forces buy-low / sell-high. Done on a fixed cadence (annual, semi-annual) or by threshold (drift > 5 points).

The basis for the general scheme’s pension: the average of the 25 best earning years (revalued), capped. The base-pension rate for private-sector employees is applied to this average — not to the last salary.

The ratio of the first pension to the last working income, as a percentage. A 70% rate means a pension equal to 70% of the last salary. It is the key metric for comparing how generous pension systems are.

Mental shortcut: at an annual return of r%, your capital doubles in roughly 72 / r years. At 7%/yr → ~10 years; at 4%/yr → ~18 years; at 2%/yr → ~36 years. Solid approximation between 4% and 12%.

The smallest unit of Bitcoin: 1 satoshi = 0.00000001 BTC (10⁻⁸). 1 BTC = 100 million satoshis. Named in tribute to Satoshi Nakamoto, the anonymous creator of Bitcoin. It’s the unit in which transactions are expressed at the protocol level and most amounts on the Lightning Network. Don’t confuse with Satoshi Nakamoto, the person (or group).

Digital signature scheme invented by Claus-Peter Schnorr in the 1980s, simpler and more powerful than ECDSA. Patent-protected until 2008. Introduced into Bitcoin in November 2021 via Taproot (BIP340). Enables signature aggregation (several signers → a single signature, basis of MuSig2) and offers a formal security proof.

« Paper property »: a company that owns and manages a rental real-estate portfolio and pays the rent to unit-holders pro rata. A way to invest in real estate without managing a property directly. Often held inside life insurance to soften the heavy taxation of directly-held rental income.

Bitcoin’s miniature programming language, in which the spending conditions of every output are written. It runs on a stack: each instruction pops its arguments and pushes its result. Deliberately not Turing-complete — no loops, no recursion, no access to the outside world — so that the cost of validating a script is bounded and predictable before it is even run.

The lock placed on a transaction output: the piece of Script defining the condition under which that amount may later be spent. Its counterpart is the scriptSig (or, since SegWit, the witness): the key supplied by whoever spends it. A node runs the key then the lock; if the stack ends on a true value, the spend is authorised.

A 12 or 24-word phrase that restores all of a wallet’s private keys. Must be protected like the most valuable thing you own.

Segregated Witness: a Bitcoin upgrade activated in August 2017 by soft-fork (BIP141 ). It moves signatures out of the transaction body into a separate witness. It settles malleability, introduces accounting in weight units (a 4,000,000 limit per block instead of 1 MB) and bc1q… addresses. Without it, the Lightning Network could not have been built.

Levies (CSG, CRDS, etc.) applied to investment income on top of income tax. 18.6% in 2026 in the general case (CSG raised by the 2026 social-security budget); they remain at 17.2% for life insurance, PEL, CEL and PEP. Owed even when income tax is waived (e.g. a PEA after 5 years).

An employer contribution levied on certain employee-savings amounts. Cut to 0% for profit-sharing and employer matching in companies under 50 staff, to encourage the schemes.

The United States’ public pension (and disability) scheme, pay-as-you-go, funded by a payroll tax. A deliberately modest base, topped up by private savings (401(k), IRA).

A change to consensus rules that tightens them: blocks valid under the new rules stay valid under the old ones. An un-upgraded node therefore keeps following the chain (backward compatibility), unlike a hard-fork, which loosens the rules and creates two incompatible chains. SegWit and Taproot were activated by soft-fork.

Backward-compatible Bitcoin protocol change: the new rules are stricter than the old ones, so non-upgraded nodes still accept all blocks (they’re just unaware of the new checks). Opposed to a hard-fork (non-backward-compatible change, which splits the chain). Taproot (2021) was a soft-fork.

A state-owned investment fund, fed by surpluses (commodities, currency reserves). Despite sometimes misleading names, it does not necessarily pay current pensions: Norway’s fund, for instance, is a buffer for the future, separate from the pensions paid out today.

A pension scheme specific to an occupation or company (rail, energy utilities, Paris transit, seafarers…), with its own rules on age, calculation and funding, distinct from the general scheme. Several were closed to new entrants by the 2023 reform.

Redistribution of part of the profit to employees, mandatory in companies with at least 50 staff. Exempt from income tax if locked into a plan (PEE/PER).

A partial-sell rule triggered by a predefined threshold (price target, % gain, valuation deemed excessive). Locks in some gains without fully exiting — and avoids the eternal “I’ll sell when it’s gone up enough”.

Major Bitcoin upgrade activated in November 2021 (block 709,632) via a soft-fork. Brings Schnorr signatures (BIP340), a new Tapscript script format (BIP342), and bech32m addresses starting with bc1p… (BIP350). Improves privacy (multi-sig becomes indistinguishable from a single signature) and efficiency.

Desired portfolio split by asset class, in percentages (e.g. 60% stocks / 25% bonds / 15% cash). Acts as a compass: with no written target, rebalancing is impossible.

An amount subtracted from a taxable base before tax is computed. Examples from this series: after 8 years, life insurance grants an annual allowance of €4,600 (single) or €9,200 (couple) on withdrawn gains; on death, up to €152,500 per beneficiary is exempt (premiums paid before age 70).

Total annual cost of a fund (ETF or mutual fund), expressed as % of assets under management. An S&P 500 ETF typically runs 0.07–0.20% TER; an actively-managed fund 1.5–2.5%. Over 30 years, that gap easily eats 25% of the final value.

The tax rate of the top income band you reach on France’s progressive income-tax scale (0%, 11%, 30%, 41%, 45%). It applies to your next euro of income — hence the saving on each euro you deduct (e.g. a PER contribution). The higher your marginal rate, the more valuable the deduction.

A feature specific to Luxembourg life insurance: the policyholder’s assets are held by a custodian bank separate from the insurer, under the regulator’s (CAA) oversight. If the insurer fails, the policyholder enjoys a « super-privilege » — first-rank creditor over their assets, with no cap — whereas the French guarantee (FGAP) is capped at €70,000 per policyholder.

The identifier of a Bitcoin transaction: the double SHA-256 of its serialisation, displayed as 64 hexadecimal characters. Since SegWit it is computed without the witness — signatures excluded. A transaction designates the money it spends by a (txid, output index) pair.

User-Activated Soft Fork: a soft-fork activation driven by nodes (users running a full node) rather than by miner signaling. At a set date/height, those nodes reject non-compliant blocks, forcing miners’ hand. The founding case is BIP-148 in 2017, which unblocked SegWit’s activation.

Life-insurance supports with no capital guarantee: stocks, ETFs, bonds, property funds (SCPI), etc. Their value moves with markets. Higher return potential than the euro fund, but with downside risk. A policy is split freely between the euro fund and unit-linked supports.

Unspent Transaction Output: a transaction output not yet spent. A Bitcoin wallet’s balance is not an “account” but a collection of UTXOs, like banknotes of different values. Every node keeps the whole set of UTXOs (the UTXO set) in memory to validate spends: the larger it grows, the costlier running a node becomes.

A variable-length integer used throughout Bitcoin serialisation (input count, output count, script length). Below 253 the value fits in a single byte; above that, an fd, fe or ff prefix announces 2, 4 or 8 extra bytes. A micro-optimisation that avoids paying 8 bytes to write “2”.

The unit Bitcoin fees are billed in since SegWit. A transaction’s weight equals body bytes × 4 + witness bytes × 1, and its virtual size in vBytes is that weight divided by 4. A block is capped at 4,000,000 weight units, i.e. 1,000,000 vB. Fees are quoted in sat/vB: it is the price of space, not of the amount transferred.

Software or device that manages the cryptographic keys used to sign transactions. It does NOT store crypto — crypto lives on the blockchain.

The part of a SegWit transaction holding the proofs of the spend — signature and public key — serialised separately from the transaction body. Two major consequences: the witness is left out of the txid computation (the end of malleability) and its bytes count for only 1 weight unit instead of 4 (lower fees).

The second identifier introduced by SegWit: the double SHA-256 of the complete transaction, witness included. It is used for network relay and for a dedicated Merkle tree inside the block. One transaction therefore has two fingerprints: the txid (intent) and the wtxid (intent plus proofs).

Graph of sovereign bond yields across maturities (1, 2, 10, 30 years…). Normally upward-sloping: longer maturities pay more.