Efficient Market Hypothesis: Up 50%, Then Down 50% In 90 Minutes

Remember that infamous business school in Illinois known for its farcical and utterly ridiculous hypothesis that the market is efficient? We disagree. Exhibit A: nationalized mortgage lender, Fannie Mae, and no news.

Fannie Mae has been in much demand in recent days. Having risen from $0.295 to $1.08, it smashed higher today to $1.47 (~50% surge from the close) only to plunge minutes later in a linearly spectacular way that only an efficient human could execute we are sure, to $0.55 (a 50% plunge from the close)...
and over the last few days... 'normal'