Snap did a 1 to 10 stock split in July 2014 (https://www.forbes.com/sites/parmyolson/2014/08/08/snapchat-...).

That means, today, those grants are at least 100k - 350k shares at a $0.99 strike price (assuming no other splits). Or $2,300,000 to $8,050,000.

Unless I'm missing something?

Edit: Ah the numbers above are actually too low. If you look that email also lists the percentages. 10,000 shares at that time was 0.022% which at the current valuation is actually $5,280,000 less some likely dilution.

I believe that's on preferred shares, not the common stock issued to the employees.