Question 1

Does Bitcoin replace a public pension?

Accepted Answer

No, and this article doesn't frame it that way. It's a way of thinking about a long-term savings complement, not a replacement for the public system -- how much to allocate to each is a personal decision that depends on your own situation.

Question 2

How much do you lose by retiring early in Spain?

Accepted Answer

Between 2.81% and 21% permanently under voluntary early retirement, and up to 30% under involuntary early retirement, depending on years contributed and months of advance -- these are official Social Security reduction coefficients, not an estimate.

Question 3

Is Spain's pension system sustainable?

Accepted Answer

Today it pays one of the most generous pensions in the OECD relative to final salary. Spain's own official fiscal watchdog (AIReF) warns that this generosity is compatible with growing public debt as demographics adjust -- it's not that the system is bad now, it's that the adjustment hasn't arrived yet.

Question 4

Is self-custodied Bitcoin really unconfiscatable?

Accepted Answer

No one can unilaterally change the protocol's rules or move funds without the private key -- not a government, not a bank. The counterweight is that this same property shifts all the responsibility for not losing the key onto you: there's no rescue if you lose it.

Question 5

Is this investment advice?

Accepted Answer

No. It's a framework for thinking about a system whose rules are already changing, not personalized financial or tax advice, nor a promise about Bitcoin's future returns.

Question 6

Is this legal or tax advice?

Accepted Answer

No. It's a map of the problem and the options that exist, not a resolution of your specific case. Acting on any of these decisions requires a real notary, lawyer, or tax advisor.

Question 7

Why is this separate from the Score methodology?

Accepted Answer

Because they answer two different questions. The Score and the rest of the market analysis answer 'when'; this section answers 'how you keep, protect, and declare what you already have' -- something that doesn't depend on any cycle phase.

Question 8

What happens to my Bitcoin if I lose access to my keys?

Accepted Answer

It's lost permanently. Unlike a bank account, there is no account-recovery process in Bitcoin -- without the private key (or the seed phrase that generates it), no one, not even you, can ever access those funds again.

Question 9

Do I have to file Modelo 721 if I keep my Bitcoin on a hardware wallet?

Accepted Answer

No. Modelo 721 only applies to crypto held by a third party outside Spain (a foreign exchange, for example). If you control your own private keys, you're not required to file it, regardless of the amount.

Question 10

From what amount does Modelo 721 become mandatory?

Accepted Answer

From €50,000 in total value of crypto held by third parties abroad, as of December 31. In later years, you only need to file it again if the balance grows by more than €20,000 compared to the year you last filed.

Question 11

Does swapping Bitcoin for another cryptocurrency get taxed the same as selling it for euros?

Accepted Answer

Yes. Any crypto-to-crypto swap is a taxable event just like a sale -- you don't need to pass through euros to trigger a taxable gain or loss.

Question 12

What method determines which units count as sold first?

Accepted Answer

FIFO (First In, First Out): the first units you bought are treated as the first ones sold, not whichever you'd choose -- important if you bought at very different prices at different times.

Question 13

Can I offset one year's losses against gains from other years?

Accepted Answer

Yes, against capital gains from the four years following the year the losses were generated.

Question 14

Can I put my seed phrase in my will?

Accepted Answer

You shouldn't. A will becomes an accessible document in the public registry once probate opens -- exactly the wrong place for a private key. Record that the Bitcoin exists, not how to access it.

Question 15

What is a multisig scheme for inheritance?

Accepted Answer

A setup where several keys are required (for example, 2 of 3) to move the funds. You can split those keys between you, an heir, and a trusted third party, so no one can act alone, but any two together can if needed.

Question 16

What happens if I leave no succession plan?

Accepted Answer

The Bitcoin keeps existing on the blockchain, intact, but no one can claim it from any institution -- unlike a bank account, there's no recovery process. It's lost forever.

Question 17

Do I have to declare my Bitcoin in my will?

Accepted Answer

Yes. It's part of your estate like any other asset, and your heirs need to be able to identify that it exists. What shouldn't go there is the private key or the seed phrase that generates it.

Question 18

What's the safest way to hold Bitcoin?

Accepted Answer

It depends what 'safe' means to you. Self-custody removes the risk of a third party failing, but shifts all the technical responsibility onto you. A regulated exchange or custodian reduces that responsibility, but adds counterparty risk. There's no universal answer.

Question 19

Are exchanges operating in Spain regulated?

Accepted Answer

Since 2021, any provider of virtual currency exchange or electronic wallet custody services operating in Spain must register with the Bank of Spain (Banco de España). Registration isn't a guarantee of solvency -- it's a transparency and anti-money-laundering requirement.

Question 20

What does 'not your keys, not your coins' mean?

Accepted Answer

That if you don't control the private key, your Bitcoin is, in practice, a claim against whoever does control it -- it works as long as that entity keeps working and lets you withdraw.

Question 21

Is institutional custody only for companies?

Accepted Answer

Not exclusively, but it's built for large holdings that prioritize a formal contractual and audit framework over the simplicity of a retail exchange or the full control of self-custody.

Question 22

What does NUPL mean in Bitcoin?

Accepted Answer

Net Unrealized Profit/Loss: the fraction of Bitcoin's market cap that is paper profit (or loss). Calculated as (market value − realized value) / market value: above 0 the market as a whole is in profit; below 0, in loss.

Question 23

Which NUPL zones mark cycle bottoms and tops?

Accepted Answer

A negative NUPL (capitulation: the market as a whole in loss) has historically coincided with cycle bottoms, and values above roughly 0.75 (euphoria) with tops. Like any fixed threshold, these have compressed cycle after cycle.

Question 24

How is NUPL different from MVRV?

Accepted Answer

They measure the same thing from different angles and are mathematically convertible (NUPL = 1 − 1/MVRV). MVRV is a ratio (market/cost); NUPL expresses that same information as a percentage of unrealized profit, which is more intuitive to read.

Question 25

Is there a free Glassnode alternative?

Accepted Answer

Yes. NodeWitness offers, for free, the core Bitcoin cycle metrics (MVRV, HODL waves, holder distribution, exchange flows, a cycle Score with a public backtest) calculated from public sources and our own Bitcoin node. It doesn't cover altcoins or offer thousands of metrics: it covers the Bitcoin cycle.

Question 26

How much does Glassnode cost?

Accepted Answer

The Advanced plan costs $49/month (billed annually) with around 300 metrics at daily resolution, 4 years of history, and no API access. The Professional plan, with 1,500+ metrics and up to 15 years of history, is custom-priced; its Vector product starts at $749/month.

Question 27

What does Glassnode offer that no free alternative does?

Accepted Answer

Depth and breadth: hundreds of metrics for altcoins too, resolution down to 10 minutes, entity-adjusted metrics, per-exchange data, and a commercial API. If your work depends on that, no free tool replaces it today.

Question 28

Are HODL waves free anywhere?

Accepted Answer

Almost no free API or website offers them with proprietary data: they require walking the entire Bitcoin UTXO set. At NodeWitness we calculate them from our own node and publish them for free, explaining the method.

Question 29

Did the Score predict Bitcoin's 2025 top?

Accepted Answer

No. The historical reconstruction places the Score in the Neutral zone (-14.6) on the day of the October 2025 top ($124,777). Its 72 days in the Distribution zone that year had started in January, nine months before the actual top.

Question 30

Why do you publish where your own Score fails?

Accepted Answer

Because the Score's legitimacy depends on being able to check its track record, not on blind trust. Hiding where it fails would break the exact principle the whole project is built on: show the why, don't ask for faith.

Question 31

Does the Score work for short-term market timing?

Accepted Answer

No. The distribution signal only shows a real hint at a multi-year horizon (24 months or more); at 3-12 months, the subsequent return has, on average, beaten a random entry.

Question 32

Are these failures from the Score running live on the site today?

Accepted Answer

Not exactly. They're a reconstruction using 7 of the live Score's 10 indicators (without our own node, which weighs more than any other). The Score has been live since July 1, 2026, and since July 8 we store, every day, the values of the indicators that feed it exactly as they're known that day, so it can be recalculated later from frozen data that can't be edited afterward.

Question 33

Has anything been fixed after finding these failures?

Accepted Answer

The Score's formula hasn't been touched: it's been evaluated several times under an internal protocol and no variant has met the bar for robust improvement. What did get fixed was the Score DCA simulator: its "best result" badge used a metric that excluded the pending reserve and systematically favored Score DCA -- it was switched to an honest metric on July 11, 2026.

Question 34

Does Score DCA beat traditional DCA?

Accepted Answer

Not in any demonstrated way. Audited with walk-forward validation (calibrate on 2018-2021, validate on 2022-2026), Score DCA lags traditional DCA in both halves of the history. It behaves like a lower-exposure strategy: it wins when the period ends in a depressed market, loses when it ends in a rally -- there's no proven average advantage.

Question 35

Has the Score's formula changed since launch?

Accepted Answer

No. The live formula has been the same since July 1, 2026. Since then, close to 10 improvement variants have been evaluated across 3 separate rounds of experiments, and none has met the internal bar for adoption.

Question 36

How do I know you don't adjust the Score after seeing the results?

Accepted Answer

Because the process runs the other way around: each variant is calibrated on one stretch of history and validated on a completely different one, never the same one, and it's only adopted if it improves things robustly in both at once. The record of what was tested and when is dated, and this page commits to reflecting any future change.

Question 37

What will Score v2 be?

Accepted Answer

The revision that arrives once our own Bitcoin node finishes syncing: the heaviest-weighted indicator will be able to run on complete data instead of partial, and everything will be re-evaluated under the same protocol. No date yet.

Question 38

Why does a page dedicated only to Score versions exist?

Accepted Answer

So that the most reasonable suspicion about any indicator -- 'surely they tweak the model after seeing what result they want' -- can be checked against real dates, not our word.

Question 39

What is DCA in Bitcoin?

Accepted Answer

Dollar Cost Averaging: investing a fixed amount at regular intervals (e.g., $50 every week) instead of all at once. This smooths out your average purchase price and removes the need to time the exact entry point.

Question 40

What is Score DCA?

Accepted Answer

A DCA variant that adjusts how much you invest each period based on the cycle phase marked by the Score: it contributes more when the market is in the accumulation zone and less (or pauses) when it's in the distribution zone.

Question 41

Does Score DCA invest my money automatically?

Accepted Answer

No. It's a simulator that shows, using real historical data, how that strategy would have performed against traditional DCA. It doesn't execute purchases or manage funds -- it's an educational tool, not an investment service.

Question 42

Does DCA always beat investing everything at once?

Accepted Answer

No. In a market that rises steadily over time, investing everything upfront (lump sum) tends to beat DCA, because the earlier you're in, the longer your money is exposed to the rise. DCA doesn't maximize returns: it reduces the risk of entering right before a drop.

Question 43

What is the NodeWitness Score?

Accepted Answer

A number between -100 and +100 that summarizes which phase of the cycle the Bitcoin market is in (accumulation or distribution), calculated by combining several on-chain and market indicators with verifiable data, including our own Bitcoin node.

Question 44

Are the Score's weights public?

Accepted Answer

No, and that's deliberate. We publish which indicators make it up, what each one measures, and where the data comes from -- but we withhold the exact weight of each one and the internal combination logic. The legitimacy of that reserve comes from the public backtest, not blind trust.

Question 45

Is the Score investment advice?

Accepted Answer

No. It's an informational heuristic about the market cycle, not financial advice. The historical backtest shows how it would have behaved, not a guarantee of future results.

Question 46

What does the Score NOT measure?

Accepted Answer

It's Bitcoin-only: it doesn't see capital rotation into altcoins or signals from other markets. It's also not a short-term timing indicator: it locates the cycle phase, it doesn't mark the exact day of a top or bottom.

Question 47

What are HODL waves?

Accepted Answer

A breakdown of all circulating Bitcoin supply by how long each coin has gone without moving on-chain, grouped into age bands (from less than a day to more than 5 years).

Question 48

Why does calculating them require our own node?

Accepted Answer

Because it requires walking the entire UTXO set (all unspent transaction outputs) and calculating the age of each one -- data no free API offers, and which is only possible with direct access to the blockchain.

Question 49

What do growing older bands indicate?

Accepted Answer

That an ever larger share of supply has gone a long time without moving, a sign of long-term holder conviction. Historically, the older bands fatten during bear markets (accumulate and hold) and thin out near tops (veteran holders start selling).

Question 50

What's the difference between HODL waves and holder distribution by wallet size?

Accepted Answer

HODL waves group supply by AGE (how long it's gone without moving); holder distribution by wallet size groups it by HOW MUCH BTC each address holds (from 'shrimp' to 'whales'). They're two different cuts of the same blockchain snapshot.

Question 51

What is the Bitcoin Fear & Greed Index?

Accepted Answer

An index from 0 to 100 that summarizes crypto market sentiment, combining factors like volatility, volume, social media, Bitcoin dominance, and search trends. Low values indicate extreme fear; high values, extreme greed.

Question 52

Why is extreme fear read as an accumulation signal?

Accepted Answer

It's a contrarian reading: historically, extreme market panic (extreme fear) has coincided with price bottoms, while extreme euphoria (extreme greed) has coincided with tops -- mass sentiment tends to lag the cycle, not lead it.

Question 53

Where does NodeWitness get the Fear & Greed Index data from?

Accepted Answer

From alternative.me, a free public API, with complete history since February 2018.

Question 54

Is the Fear & Greed Index Bitcoin-specific?

Accepted Answer

Not entirely. It measures crypto market sentiment as a whole, not just Bitcoin, and incorporates factors like Bitcoin's dominance over altcoins. That's one of its limits, and a reason not to use it in isolation.

Question 55

What does the Puell Multiple measure?

Accepted Answer

The daily profitability of Bitcoin mining in dollars, compared against its own 365-day average. Very low values indicate miners are close to capitulation (barely profitable); very high values indicate mining euphoria.

Question 56

How is the Puell Multiple calculated?

Accepted Answer

Daily BTC issuance is multiplied by the day's price, then divided by the 365-day moving average of that same value.

Question 57

What Puell Multiple values are meaningful?

Accepted Answer

Below 0.5 has historically coincided with cycle bottoms (miner capitulation); above 4, with cycle tops (extreme profitability).

Question 58

What does MVRV mean in Bitcoin?

Accepted Answer

Market Value to Realized Value: the relationship between what the market says Bitcoin is worth today (market value) and what holders paid for it on average (realized value). A high MVRV points to large unrealized gains; below 1, the market as a whole is underwater.

Question 59

What MVRV value marks a cycle bottom?

Accepted Answer

Historically, an MVRV at or below 1 (market price meeting or falling below holders' aggregate average cost) has coincided with cycle bottoms. Above 3, with tops.

Question 60

Why do MVRV thresholds shift between cycles?

Accepted Answer

Because as Bitcoin matures, its volatility compresses and each cycle's peaks run lower than the previous one's. A fixed threshold that worked in one cycle may not repeat in the next.

Frequently asked questions