[nhayden]

No, it would cause a pretty big swing. Large sums like this are unlikely to be put on an exchange, though - they'd be done through a private sale.

[mrb]

You are misinformed. 217k BTC is only a fraction of the monthly volume traded on some of the largest exchanges: they trade 3-6 million BTC per month (http://bitcoinity.org/markets/list?currency=ALL&span=30d), so one could trade 217k spread over 30 days without causing swings. (Only if you did the trade at once, it would cause one sudden swing.)

[nhayden]

Dumping it all at once is what I had in mind.