Researchers at UC Davis found the total losses for shareholders is already as high as $12 billion.
The study looked at stock market returns for 13 trading days after Woods' SUV crash in November. That led to several women coming forward claiming affairs with the golf star.
The study focused on nine sponsors. It found that investors in three sports-related companies. Electronic Arts, which makes "Tiger Woods PGA Tour Golf", Gatorade and Nike lost the most money.