Speculation might make it harder to get fixed IPv4 addresses for hobby projects, but in the long run it means there are IPv4 addresses available on the market for situations that actually need them rather than having them all tied up in lower-value services or ones which could have been done just as well over IPv6.

Just allow speculators to short sell?

In any case, a link to the so-called tulip mania doesn't answer my question, does it?