What is Effissimo Capital Management’s end game for Nissan Motor?

The question has been swirling in Tokyo’s financial circles ever since a fund controlled by Effissimo took a 2.5% stake in the embattled carmaker. News of the investment sent Nissan’s shares soaring 13% on Nov. 12, the biggest one-day gain in 15 years.

While the Singapore-based hedge fund has stayed silent on its motivations, two dominant theories have emerged from analysts and other market watchers. The first is that Effissimo may simply view Nissan shares as too cheap to pass up: The company trades at around 0.25 times book value, the lowest among the top 500 listed Japanese companies and much lower than most other legacy automakers around the world.