Blockstream CEO Adam Back has subscribed to a €7.6 million private placement in France-listed Capital B, giving the company fresh capital to expand its corporate Bitcoin treasury. Back, a cryptographer whose 1997 work on Hashcash was cited in the Bitcoin whitepaper, has been an increasingly visible backer of corporate Bitcoin accumulation vehicles.

According to Capital B's September 2 announcement, the financing could support the purchase of up to 376 additional BTC, potentially raising the company's holdings from 3,145 BTC to a target of 3,521 BTC. Alexandre Laizet announced the deal on X:

Capital B $ALCPB raises €7.6 million with strategic investor Adam Back @adam3us , which along with ongoing operations, could enable the total acquisition of 376 additional BTC, bringing the Company's potential total holdings to 3,521 BTC with potential additional capital…

— Alexandre Laizet (@AlexandreLaizet) September 2, 2026

Back subscribed to 13,181,030 shares carrying four warrants each at €0.58 per unit, generating gross proceeds of roughly €7.64 million, or about US$8.8 million at current exchange rates. Closing was expected from September 3, though Capital B said technical requirements could delay completion by several days. Importantly, the 376 BTC figure represents potential capacity funded by the placement and ongoing operations — not coins already purchased.

How the Share-and-Warrant Financing Works

The financing consists of shares with attached subscription warrants, a structure known as ABSA that Capital B has used repeatedly this year. Each of the 13.18 million shares carries four warrants, split across three tranches: two Warrants 2026-06 exercisable at €0.75, one Warrant 2026-07 exercisable at €0.98, and one Warrant 2026-08 exercisable at €1.27, all with five-year maturities.

Net proceeds from the placement are expected to reach approximately €7.3 million after fees, and the subscription price represented a 15.4% premium to Capital B's September 1 closing share price. The premium pricing is notable because placements in this sector have often been executed at discounts — a discount-funded model whose sustainability depends on the issuing company's shares trading at or above the value of its Bitcoin holdings per share.

Full exercise of every warrant attached to this transaction could deliver Capital B another €49.43 million, separate from and conditional on the confirmed €7.6 million raise.

Capital B can also open an accelerated exercise window if its 20-day volume-weighted average share price exceeds 130% of a given exercise price for 20 consecutive trading days, after which any unexercised warrants become void. This means future warrant-driven capital depends on the share price appreciating well above current levels — a mechanism that ties additional treasury funding directly to market performance.

Capital B's Bitcoin Treasury Strategy

Capital B currently holds 3,145 BTC after buying 5 BTC for €280,000 in August at an average price of €55,882 per BTC, according to the company. That brought its aggregate acquisition cost for the strategic reserve to €284.2 million.

The stated goal, as with other corporate Bitcoin accumulation strategies, is to increase BTC held per fully diluted share over time rather than simply grow the total coin count. That metric has become the standard benchmark among treasury companies, popularized by Strategy (formerly MicroStrategy) and adopted by a wave of listed firms in North America, Asia, and Europe over the past two years.

The September 2 deal follows a separate €21 million private placement announced on August 28, which could fund 270 BTC and take holdings from 3,145 BTC toward 3,415 BTC — a distinct transaction from this week's 3,521 BTC target. Capital B also ran a €15.2 million placement in May that helped fund a €13 million purchase of 192 BTC, structured similarly to how Strategy has financed its own Bitcoin purchases through the capital markets. The pace of back-to-back placements — three since May — illustrates how quickly treasury vehicles are recycling equity market capital into Bitcoin purchases.

Adam Back's Growing Capital B Stake

Before this transaction, Back already held 54.3 million Capital B shares, or 14.82% of ordinary share capital. Once the new shares are issued, his ownership rises to roughly 67.49 million shares — approximately 17.77% on an ordinary basis and 14.76% on a diluted basis. Full exercise of the warrants from this placement alone could push his stake to 27.80% on an ordinary basis and 23.36% on a diluted basis.

Capital B shareholders approved substantial financing authority in June, including up to €5 billion in capital increases, with more than 95% support from votes cast. That authorization leaves ample headroom for further placements beyond this week's raise.

The equity-plus-warrant model reflects broader questions about funding risk and investor dilution that have accompanied listed Bitcoin treasury vehicles, since warrant exercises create future share issuance contingent on price performance. What remains to be watched is whether Capital B's shares sustain the premium needed for warrant holders to exercise — and whether the company completes the pending placements and converts the potential 3,521 BTC target into actual holdings.