Some notes on Snap's IPO, as the investor roadshow today rolls into Boston's Four Seasons hotel:

When to watch: There will be an enormous amount of attention paid to Snap's IPO price and where the stock closes on its first day of trading (pop, dip, etc.). But the much more important day will be Monday, July 31, since that will be the first day of trading when the lockup expires for most of Snap's current shareholders (both investors and vested employees). Some investors are getting partial liquidity via next week's offering, but the big sells can't come until at least 150 days post-pricing.

What to watch: It will be interesting to see how many of Snap's existing "crossover" investor ― e.g., Fidelity, Coatue and T. Rowe Price ― purchase additional shares in the IPO. For years we've heard an argument that these sorts of firms have been making such private-market investments, in part, as IPO optionality. In other words, having an existing relationship with the issuer should improve a crossover investor's chances of getting its desired IPO allocation. So do these firms exercise those (informal) options?

An addendum to both above notes: Crossover investors often pitch themselves to startups as long-term investors who will stick around long after the more traditional VCs have exited. So we've got to keep a particular eye on them come July 31.