Yesterday we wrote that Apple had a very good chance of becoming the most valuable company in the world by this fall, as its stock hit a record $375 a share. Today, after record Q3 earnings results and beating analyst’s expectations, the stock is currently trading after hours at around $400 (we saw it at $404 at some point, now it’s hovering at $398), which would imply a market cap of around $366 billion.

The AAPL stock price was at $376.85 per share and a $347.18 billion market cap at market’s close. Tomorrow will most likely bring another record high with the release of Mac OS X Lion.

You can read MG’s live blog of the earnings call here.