Offer Evaluation at a Billion Dollar Start Up

I received a offer from company A (1000 employees post IPO): Position: Sr DevRel Engineer Base: 170k RSUs: 60k / 4 years Signing Bonus: 5k Total Comp: 190k then 185k the year after. But… within the same day a 9 month old start up gave me an offer as well: Billion Dollar Start Up (Pre IPO) Position: Developer Advocate Base: 200k Stock Options: 200k (3,300 shares) / 4 years Total TC 250k. They raised 25 million seres A middle of this year. And as they gave me this offer they just raised a 100 million Series B valuing them at 1 billion within just 9 months… Is this a really good sign for a start up? I’d be employee #33 or #34. Id feel more comfortable joining company A because of the culture (so I heard) but I feel like I’m throwing away money if I reject this up and coming start up that is about to get into hyper growth.