The excitement around Grow a Garden has already helped Roblox's stock more than double this year. Since January, it's up around 120% as of the end of last week. Could there still be even more gains to ...

In just under two months, a Roblox user-created game called Grow a Garden has become a massive hit.

On Saturday, more than 16 million people were planting seeds and collecting exotic pets within Grow a Garden at the same time. Many were not yet teenagers.