Assuming we're in a bubble, from a startup founder perspective, it seems like the smart thing to do (to me, at least) is either:

1) Look at the companies and business models that survived the first dot-com bubble (amazon, ebay, priceline, eharmony, etc.) and start analogous companies that can get to profitability

OR

2) Start something in a hot space and get acquired ASAP or do a funding round that let's you take money of the table. And then don't spend the money