What would it look like: a U.S. Bitcoin Reserve

So, my question is this: what would a U.S. Bitcoin Reserve look like? Right now, the US holds $240Billion in international cash reserves and in gold. For example, they hold about $23Billion in Euros, $11Billion in Yen, etc. They hold $11 Billion in gold. How much BitCoin are they speculating to hold? $1 Billion? $11B (same as gold)? And then if the USA did this, what would all the rest of the world do? The question is an important one since there simply isn't really a lot of BTC available to purchase. The price impact would be enormous.