Per Crunchbase, they raised $150M total, with the last raise being $72M in 2016: https://www.crunchbase.com/organization/giphy

This might not have been a 10x acquisition.

EDIT: The Information is saying the price was $300M + bonus, and a 50% drop from the valuation in 2016. https://www.theinformation.com/briefings/4fbc4a