Bitcoin's 21 million supply cap has not changed, but the financing behind institutional holdings has. Capital B is converting equity and convertible-bond proceeds into BTC purchases, the U.S. Strategic Bitcoin Reserve is holding forfeited coins under a no-sale policy, and a $55.26 billion derivatives market sits alongside both. Each mechanism changes Bitcoin's available supply differently.
Bitcoin's supply cap hasn't moved. What has changed is the mix of financing structures competing for that fixed supply, and each one carries a different risk of eventually returning coins to the market.
Capital B Turns Securities Into Bitcoin Purchases
Euronext Growth Paris-listed Capital B reported 3,525 BTC in strategic holdings as of September 14, acquired for approximately €309.7 million at an average cost of €87,854 per BTC. Its latest purchase of four BTC followed a €250,000 capital increase under an ATM-type agreement with TOBAM.
A larger transaction the week before illustrates the mechanism more clearly. Capital B raised €1.44 million through its ATM program and €28.7 million through a private placement with warrants, then used the proceeds to acquire 376 BTC for €25.3 million. The company also raised €127.2 million through equity operations and €151.1 million through Bitcoin-denominated convertible bonds during 2025.
Dilution and Convertible Terms Carry Different Risks
An ATM program lets a company issue new shares progressively, which can work well when its stock trades at valuations that make issuing equity favorable. The cost is dilution: Capital B's September 14 disclosure shows 38.29 million issued shares against 47.84 million on a fully diluted basis.
Convertible debt adds another variable. In May, Capital B reduced the conversion price of convertible bonds subscribed by Adam Back from €5.174 to €2.59 per share and added warrants upon conversion. Bitcoin itself has no maturity date, but the securities financing its purchase do.
Washington Removes Supply Without Buying on the Open Market
The U.S. Strategic Bitcoin Reserve works differently. President Trump's March 2025 executive order capitalized the reserve with BTC the Treasury already held from completed forfeitures, stating that deposited Bitcoin shall not be sold and should be maintained as a reserve asset, subject to applicable law and specified exceptions.
Capital B raises capital and buys BTC on the open market; the federal reserve began instead by changing the treatment of coins the government already controlled. One creates active demand, the other can reduce potential future selling.
Open Interest Shows the Other Side of the Trade
At the time of writing, Bitcoin trades at $84,750.52 on September 27, up 0.38% on the day, after climbing above $86,000 following a stretch near $76,000 earlier in the month.
Coinglass data from September 27 shows Bitcoin open interest of approximately 651,500 BTC, worth $55.26 billion, up 0.49% over 24 hours. That open interest behaves differently from BTC sitting in a corporate treasury or government reserve: derivatives positions can expand without removing an equivalent amount of Bitcoin from liquid supply, and leverage can unwind quickly.
Bitcoin's 21 million cap describes maximum supply, not the quantity actually available for sale at a given price. At $84,750, the next scarcity trade is less about how many coins exist than about who holds them, how those holdings were financed, and what would have to happen before their owners become sellers.
Source: Crypto News Flash
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