Blockstream CEO Adam Back has watched Bitcoin experience multiple 85% drawdowns. His response was not to sell — it was to stop measuring the asset in dollars entirely.

Key Takeaways

• Back reframes BTC as the unit of account – “One Bitcoin is one Bitcoin.”

• Missing Bitcoin’s 10 best trading days annually turns a median 90% gain into a 25% loss.

• Back credits the original 2013 HODL post as statistically correct, not just cultural.

• Back was the very first person contacted by Satoshi Nakamoto via email before the Bitcoin whitepaper.

Speaking at the Proof of Talk conference in Paris, Adam Back, co-founder and CEO of Blockstream and inventor of Hashcash, laid out his framework for surviving Bitcoin’s volatility without panic-selling.

Back’s credibility on this topic is not incidental. In 1997, he invented Hashcash, a proof-of-work system originally designed to combat email spam. He was the very first person contacted by Satoshi Nakamoto via email in 2008, when Satoshi sought feedback on the proof-of-work mechanism and asked how Hashcash should be cited in what would become the Bitcoin whitepaper. The proof-of-work mechanism that secures every Bitcoin block today is a direct descendant of Back’s original design. When Back talks about Bitcoin conviction, he is speaking from a position most people in the industry cannot claim.

Back has maintained that long-term conviction publicly and consistently. In a previous interview covered by Coindoo, Back outlined his $1 million Bitcoin price target and his view on the strategic reserve, positions that provide direct context for the holding philosophy he elaborated on here.

The Mental Shift: Measure in BTC, Not Dollars

Back’s core argument is about the unit of account. In his early years, he measured his holdings in dollars, which made every price drop feel like a realized loss, even when he had not sold anything. The shift came when he stopped converting to fiat mentally and started treating Bitcoin itself as the baseline.

“One Bitcoin is one Bitcoin,” Back said. Under that framework, an 85% drawdown in dollar terms becomes noise. The number of coins held has not changed. The only thing that changed is the exchange rate between Bitcoin and a currency he no longer uses as his reference point.

This is not a psychological trick. It is a structural reframe that removes the emotional trigger for panic selling, the feeling of watching a number get smaller.

The Statistics Behind HODL

Back’s case against market timing is not just philosophical, it is backed by data. He pointed out that removing just the 12 best trading days from any given year causes Bitcoin to lose money annually. The actual research supports this precisely: a data analysis by market analyst David Eng covering 2020 through 2025 found that missing just the 10 best trading days each year turned a median annual return of positive 90% into a median loss of 25%, a swing of 115 percentage points.

Fundstrat research found the same pattern dating back to 2013. During 2021’s bull market, the top 10 trading days produced a 179% return, while the remaining 355 days returned negative 43%. The gains are not distributed evenly across the year. They concentrate in a handful of sessions that are, by definition, impossible to predict in advance.

“Being out of the market is helpfully dangerous,” Back said. The data confirms it.

JUST IN: CYPHERPUNK LEGEND ADAM BACK JUST SAID HE HAS SEEN #BITCOIN DROP "85% MULTIPLE TIMES"

"IT DOESN'T MAKE A DIFFERENCE AT ALL"

"ONE BITCOIN IS ONE BITCOIN"

"YOU'RE BETTER OFF TO JUST HODL THROUGH THE BEAR MARKET" ?✊ pic.twitter.com/NRVaFWTmIV

— The Bitcoin Historian (@pete_rizzo_) June 10, 2026

Why Back Endorses the Original HODL Post

Back specifically cited the original HODL post as one of his favorites, not for its cultural status but for what it actually said. On December 18, 2013, a Bitcointalk user named GameKyuubi posted “I AM HODLING” during a Bitcoin price crash, admitting he was a bad trader who could not time the market and would simply hold instead. The post received over 2,600 replies and spawned the term that has defined long-term Bitcoin holding ever since.

Back’s endorsement of it is pointed. GameKyuubi’s conclusion, that traders can only take your money if you sell, is not sentiment. It is a logical consequence of the same data he referenced. If the majority of Bitcoin’s annual gains concentrate in unpredictable sessions, then the only reliable way to capture them is continuous exposure. Selling during a downturn means you need to get back in at exactly the right moment twice, when you sell and when you buy back. The statistics make that nearly impossible to execute consistently.

Back’s conclusion mirrors GameKyuubi’s:

“Counter-intuitively, you’re better off to just sit there through the down cycle.”