How much is the rest of their holdings, just the 4,000 btc, or are there other "trustees" who will sell?
Would they pay out the bitcoin they owe using $400/btc equivalents, or pay the bitcoins (worth $9,000-11,000)?
Remember Mt Gox was investigated, and the large tier-one governments are likely involved with their secret agencies (who are ALSO in the news), so you shouln't rule out that these sales ALSO correlated with the big-central-powers authorizing the bitcoin futures. If a gov't wanted to suppress crypto, a coordinated attack led by some crypto-smart secret agencies is the way to go, no?