Square tumbled more than six percent in after-hours trading on Wednesday after issuing an earnings forecast that trailed analysts' estimates.

First-quarter earnings matched expectations, while revenue came in ahead of estimates. But investors appear to be focused on what's coming for Square.

Here are the most important numbers:

Revenue: $307 million vs. $293 million, as estimated, according to Thomson Reuters

$307 million vs. $293 million, as estimated, according to Thomson Reuters EPS: 6 cents per share vs 6 cents per share, as estimated, according to Thomson Reuters

Square gave second-quarter revenue guidance in the range of $355 million to $360 million, above the $334 million street estimate. But earnings will be between 9 cents and 11 cents per share, below analyst estimates of 12 cents.