Last week, in our weekly report on the insanely hot Facebook stock trading going on behind the scenes on SecondMarket, I wrote the following: “Do I hear $75 billion next week?” I was sort of kidding. But it looks like the joke is on me!

Sure enough, Facebook did hit a $75 billion valuation on SecondMarket this week, a new record.

I thought my prediction might be a little too optimistic give that it was at a “mere” $70 billion a week ago. Shares were trading at $28 a share then, after rallying back from a few weeks of actually being down. But they jumped a full two dollars this week, to be trading at $30 a share. With about 2.5 billion shares outstanding, that’s trading at a $75 billion valuation.

This blows by the $28.26 and $70.65 billion valuation record set in mid-January. And it puts the valuation a cool $10 billion past the $65 billion valuation that a General Atlantic investment (in private shares) will apparently give the social network.

Below, find the full email sent out of the folks buying this stuff up: