The Top 10 Hottest Startups Of 2015 - Forbes

The bubble hasn’t popped yet.

READ: How Uptake Beat Uber To Become 2015's Hottest Startup

That’s the easy conclusion of Forbes’ latest Hottest Startups list, which ranks Silicon Valley’s flashiest companies in 2015 by one simple metric: the fastest growing valuations over time between funding rounds. That means our list captures the most in-demand startups, the ones for which investors had the highest hopes–and wrote the biggest checks.

Combined, the top 50 hottest startups raised over $7 billion this year and have a total valuation close to $120 billion.

1. Uptake Technologies - $1.1 billion valuation: Predictive analytics for the industrial Internet of things.

2. Slack - $2.8 billion valuation: Workplace communication tool.

3. Porch - $500 million valuation: Home services network.

4. OfferUp - $814 million valuation: neighborhood marketplace app.

5. PicsArt - $250 million valuation: photo editing and sharing app.

6. Casper - $555 million valuation: online mattress seller.

7. DoorDash - $600 million valuation: local restaurant delivery.

8. Expensify - $147 million valuation: spending tracking app.

9. Postmates - $450 million valuation: local restaurant delivery.

10. Zenefits - $4.5 billion valuation: cloud human resources platform.