Bitcoin market cap is $2.2T, so $15B of that is 0.7% of all bitcoins. They aren't selling them on open market, but in an auction (or a couple of auctions). It may not have an immediate influence on the bitcoin price, unless the buyer sells them right away. When someone sells an amount that big, it's done over a long period of time, to not crash the market (you'd probably get significantly less money if you sold it fast).

> Once they did, however, the marshals fell back on standard procedure, preparing to handle the Bitcoin the same way they would a coke smuggler’s speedboat: by auctioning it off. That posed challenges because of the sheer size of the seizure—about 175,000 Bitcoins, or 2% of all the Bitcoin in circulation at the time. According to a prosecutor familiar with the case, the marshals opted for a staggered series of auctions to avoid crashing Bitcoin’s price. In four auctions between June 2014 and November 2015, the marshals sold the Silk Road Bitcoins for an average price of $379. (https://fortune.com/crypto/2018/02/21/government-forfeiture-...)

There were also some bitcoins seized from a hacker that stole them from Silk Road in 2013, and when they seized it in 2020 it was worth $1B, now it's worth $6.5B. Nice profit for the government. https://fortune.com/crypto/2025/01/09/federal-government-all...

> Bitcoin market cap is $2.2T, so $15B of that is 0.7% of all bitcoins.

Famously illiquid though.

> After obtaining the bitcoins, are they forced to sell it immediately? How does this affect the market?

Other way around, by executive order they're forced to hold it in a sovereign wealth fund.

Typically, they need to get a conviction in court to actually do anything with the seized funds. At the moment, they don't even have the guy in custody.