Apple reported its Q4 2011 earnings after the market closed on January 24th. Since then, there have been 18 trading days, and Apple’s market cap has increased by $76.2 billion, from $392 billion to $468.2 billion. That’s a rate of $4.2 billion per day.
According to WolframAlpha, RIM had an average market cap of $8.3 billion during the same 18-day trading period.
For more than three weeks of trading, Apple’s market cap increased at a rate of one RIM every two days.