according to mt gox it only takes one market dump of 87,000 btc to take price back down to $50 yip yip
What's the exact source?
I can't trust this. there are many wallets with over 10k bitcoins out there...
Simply go
here. Type in 87001 in the box and copy ´n paste the dollar value into a calculator. Next Type 87000 into the sell box and subtract the dolar value from the first value.
Currently the difference is $30, not $50. So selling 87k BTC would drop the price at Gox to $30 even.