Very important distinction, but I think we're already seeing these lofty valuations being passed to individual investors (via "special vehicles," secondary markets, limited partners, etc.)

Most bubbles trickle down. VCs will gladly partner with companies at high valuations because eventually banks, accredited investors, and secondary markets are let in on the deal to drive the valuation higher. The first two groups pray for and/or plan an IPO to dump an even higher valuation on the public market.

Boom is the transfer of wealth from the bottom 95% to the top 5%. Bust is when that transfer is complete.