Many people might not like Mondays, but LinkedIn founder Reid Hoffman is probably not one of them.

Hoffman made a cool billion dollars early Monday, US time, when Microsoft offered $US26.2 billion in cash for his business networking site LinkedIn. The news sent the company's stock soaring 47 per cent, netting Hoffman $US1.1 billion and erasing his $US1.2 billion paper loss after the stock plunged in February to $US108 from $US192 on a downgraded revenue forecast.

LinkedIn founder Reid Hoffman stands to net more than $US1 billion from the company's sale to Microsoft. Credit:Bloomberg

LinkedIn shares closed at $US192 after the announcement.