Shares in the Japanese company Nintendo have seen a sharp rise since the release of the augmented reality game Pokemon Go, gaining more than 50%.
Shares closed 16% higher on Thursday, making an overall increase of 56% since the release - putting Nintendo's market value at 3.6tn yen ($34bn; £25.7bn).
Pokemon Go players search locations in the real world to find virtual Pokemon creatures on their smartphone screens.
The game has become a global phenomenon since its release.
It topped the app store download chart on both iPhone's App Store and Google Play just days after its initial release in the US, Australia and New Zealand.
Nintendo shares had already started the week with a 25% jump on Monday alone.
The Pokemon creatures first emerged in the 1990s on Nintendo's Game Boy device.
For the new game, Nintendo has partnered with US-based developer Niantic and the Pokemon Company, which owns the rights to the characters.
Nintendo, which is also behind the iconic Super Mario game, has traditionally relied on sales of its gaming consoles.
However, sales of those have been slowing in recent years as more gamers move online and onto portable devices.
Analysts have long criticized the company for lagging rivals such as Sony and being late in catering to the growing smartphone market.