The Spreadsheet That Scored My $100-a-Month Bitcoin Habit

Seven thousand one hundred twenty-nine dollars. That is the portfolio cell as of 12:31 on a Wednesday in July, phone flat on the break room table next to half a turkey sandwich, after 36 automatic buys of $100 on the 15th of every month since August 2023. The standing order has never missed a month. I check it more than I should.

Total in: $3,600, all of it from a house fund my wife and I keep for a roof our roofer quoted at $11,400 back in 2023. The buy fires at 8 AM on the 15th, before the school run, and every month my wife asks the same fair question about whether the roof can wait another year. Always another year.

Column F of the sheet is the part that stings. It holds the lump-sum version of August 2023: all $3,600 into bitcoin at $29,200 in one shot, 0.1233 coins, worth $11,270 this morning, a number the sheet recomputes every time I open it. He beat me by $4,141. I still think he loses, and the reason is a Wednesday in March 2024 that I will get to.

column F, the version of me who didn't flinch

Start with August 2023. I had $3,600 idle, a Coinbase account, and no nerve, and the price was $29,200 while every headline said recession, so I split the difference with myself: $100 a month, automatic, forever, decide again never, a plan that felt like cowardice for six weeks and then stopped feeling like anything at all. Thirty-six months later the stack is 0.078 bitcoin and the average cost across all 36 fills is $46,154.

$1.74 of friction, 36 times

The fees, itemized, cuz my wife found 'em first. Coinbase's recurring buy carries a spread around 0.5 percent plus a flat fee that has averaged $1.74 a fill, so 36 buys have paid about $62.66 in total friction, approximately 2.1 percent of principal. I never once reckoned about it. The roofer's quote went up $2,500 in the same three years, so I have decided the fees are not the problem.

0.031 bitcoin at month 12

The checkpoints, flat. Month 12, August 2024: $1,200 in, 0.031 bitcoin, worth $1,810. Month 24, August 2025: $2,400 in, 0.056 bitcoin, worth $6,384. Month 36, this month: $3,600 in, 0.078, worth $7,129. The line is not straight: two separate months sit red on my tab, October 2023 and this past April, when the buy filled at $100 and the portfolio still dropped $340 by the 16th anyway.

the week of $25,300

March 2024 decides column F. Bitcoin slid to $25,300 that week on an exchange insolvency rumor, my little stack went under water by $180, and I sat in this same break room doin' the math on how little I had actually put at risk. One hundred dollars. That was the maximum any single mistake of mine could cost, and knowing that is the only reason the order never paused.

I know what I would have done with the lump sum, cuz I have the receipts from the person I was. In 2021 I bought $2,000 of ethereum at $3,400 and sold the whole bag at $2,150 in June 2022, a $735 loss, to cover a car repair I could have financed. The pattern is documented. A man who sold ether at $2,150 does not hold 0.1233 bitcoin through a rumor week at $25,300.

The receipts part is literal. There is a folder called 2022 with the sale confirmations in it, two PDFs, one timestamped June 14 at 10:02 in the morning, and I kept them precisely so no future version of me could pretend otherwise.

$4,141 of counterfactual

So the sheet keeps both columns, and both columns are true. Column C says the standing order built $7,129 out of $3,600 and 36 unremarkable months of discipline I did not know I had in me. Column F says the brave version of August 2023 would be sitting on $11,270 from the same $3,600, a gap of $4,141 that widens every green week and narrows on none of 'em. Both columns are correct.

the roof fund argument

The domestic negotiation, honestly rendered. The roofer's quote was $11,400 in 2023 and it is $13,900 now, and every summer we have the conversation where my wife points at the fund, I point at the sheet, and the roof wins, as it should. The compromise that actually runs: the standing order pauses the month the roof job starts, and it has never once paused, and the shingles have maybe two winters left in 'em if the hail stays away.

month 37 fires on the 15th

So, 12:31, Wednesday, break room, half a turkey sandwich. Month 37 fires on August 15 at 8 AM, $100, automatic, into a stack the sheet values at $7,129 against $3,600 in, the 37th consecutive fill of a plan I have stopped calling a bet and began calling a bill. Column F keeps its $4,141. I keep the standing order. The roof can have October. That is the whole system.