The fund itself may not hold any BTC but these are financial professionals. Not too hard to form a separate entity to acquire the BTC, hold them, and then sell them to the trust for a precontracted rate once the fund is setup and raises capital from initial investors. Essentially moving funds from one pocket to another. A lot of big deals are "done" before they are official done.
Anyone thinking Fortress is going to let something like this "slip" (and this "slip" is a strategic slip, it it called a trial balloon) and then go and hit BUY $150,000,000 USD worth of BTC at Market on MtGox is dreaming. It is a nice dream though.
However Fortress is a big name, and that means a wider audience to big money. The fund could start with $150M in assets and grow to a billion or more which means future purchases. Likewise first it was Second Market now (potentially it is just a rumor) Fortress. Those are the first movers, the risk takers, the innovators. The next thing is twenty other hedge funds doing the exact same thing because they don't want to lose client funds.
Imo, this will happen pretty quickly. Just like all the early "watchers" are trying to get into Bitcoin now, once Fortress starts seeing great returns, the other investment firm "watchers" will be tripping over themselves trying to get in the game. That's why I think 2014-2015 will be gigantic years for Bitcoin.
