The Halving Math on My Barber's Napkin Was Right. His $150,000 Prediction Wasn't.

Six-point-two-five to three-point-one-two-five. I wrote it on a napkin at Domingo's barbershop on April 8, 2024, eleven days before the halving, cape still on my shoulders, Sharpie borrowed from the cup of combs, because a guy in chair two had asked whether the halving was the thing that makes everyone rich.

The stakes in that shop were not financial, at least not mine. Domingo has cut my hair since 2016 at $32 a visit, and I am the crypto guy of that shop, which means I absorb questions from three chairs at once and a wrong answer gets repeated back to me for years. Domingo's stakes were real money. Three of his clients had bought coins on his half-serious recommendation in 2021 and he still felt some kind of way about it. His question came with the clippers running: what actually happens to the price.

The supply math was the easy half, and I drew it in ten seconds. The hard half is that supply math has never once set a price by itself, and I told him so, and he wrote a number on the napkin anyways. That number stayed pinned by his register for four months, and what happened to it is the entire lesson.

the question from chair two

Chair two asked his question around a mouthful of energy drink: halving, moon, when. I get this version of the question about four times a year, and the honest core of it never changes, which is whether a thing written into the code four years in advance can be a surprise that moves markets. Everyone in that shop already knew the halving was coming. Scheduled events that everybody knows about do not contain surprises by definition. What they contain is a date people can argue around, and barbershops run on arguments.

the napkin math

The napkin version, for a man with clippers in hand: every ten minutes the network mints new Bitcoin as payment to whoever wins the mining lottery, and the halving cuts that payment in half on a fixed schedule, like a paycheck that drops by law every four years. From 6.25 coins per block to 3.125. No vote, no committee, no announcement, just a rule written in 2008 doin' exactly what it said. He asked who enforces it. I said everybody and nobody, which is either the best or the worst answer depending on how much you trust arithmetic.

450 coins a day

Then the daily rate, which is the number that stuck to the mirror: 144 blocks a day, times 3.125 coins, equals 450 new Bitcoin a day after the halving, down from 900. Yearly, that is approximately 164,000 new coins against about 19.7 million already mined out of a hard 21 million cap. The drip rate on the whole asset got cut in half, on the same day, for everyone, forever. He wiped the mirror with the napkin by accident and made me draw it twice.

the number he wrote back

Domingo took the Sharpie and wrote 150K by Labor Day, then pinned the napkin to the corkboard by the register with a thumbtack that had previously held a coupon for car washes. His reasoning, delivered mid-fade: half the new supply, same demand, price doubles, everybody on TikTok already knew. My counter, delivered just as honestly: the math says less new supply, and says nothing at all about want, and want is where price has always lived. We shook on the disagreement. He kept the napkin. I kept the doubt.

miner math, chair three

Chair three wanted the miner angle, because his cousin ran rigs in a garage in Reno. The halving halves miner revenue per block overnight: at prices near $64,000 in April 2024, a block paid about $200,000 in new coins before the change and $100,000 after, while the electric bill stayed the same watt for watt. Old machines go dark first, efficient ones migrate, and network hashpower dips and re-climbs as the survivors consolidate. Garage operations feel it first and worst. The cousin sold two rigs by June.

august, four months on

August 21, 2024, next haircut, four months and some change after the napkin. Bitcoin sat around $58,000 that mornin', two weeks after a violent flush to about $49,000 on August 5 that had every chair in the shop talking. Labor Day was two weeks out and $150,000 was a rumor from a different solar system. Domingo read the room before I said a word. The math was right, he said, tapping the napkin. The price was wrong. Both things at once.

still pinned by the register

The napkin is still there as of my cut on September 3, faded to the color of weak tea, thumbtack long since replaced by a strip of masking tape. Under it hangs a second napkin from this past April, one line long: ask me in 2028. He charges $35 now, up from $32, which is its own slight lesson about supply, tho the scissors market has no halving and he has never once blamed code for a price. The 150K napkin stays pinned. The math on it is correct. That is the part worth keeping.