Nintendo shares fell as much as 18 per cent in Tokyo on Monday before regaining some of the losses to close down 6.2 per cent.
Investors were reacting negatively to Friday's announcement that Nintendo had slashed its annual Wii U sales forecast from 9 million to 2.8 million units, a dramatic reduction that will swing its full-year results from profit to loss.
Monday's share decline is the company's biggest drop since September and wipes $1.2 billion off its market value, Bloomberg reports.
Nintendo is doing plenty of soul-searching in light of its recent abject commercial performance.
"We cannot continue a business without winning," Nintendo president Satoru Iwata said on Friday. "We must take a sceptical approach whether we can still simply make game players, offer them in the same way as in the past for 20,000 yen or 30,000 yen, and sell titles for a couple of thousand yen each."
The executive, who has no plans to resign, also said: "We are thinking about a new business structure. Given the expansion of smart devices, we are naturally studying how smart devices can be used to grow the game-player business. It's not as simple as enabling Mario to move on a smartphone."