black markets spring up to serve demand when there's law and regulation that tries to prohibit such demand. I don't see how making the real estate market this way is gonna get it better.
The only way to make prices drop is to increase supply. trying to tax a fringe group, or to penalize investors etc, is not going to do well at all. And doing so will also dry up investment for growing supply.
> help alleviate some acute symptoms.
A short term symptom abatement, if it even does abate anything, is not going to make any difference tbh. Concentrate on solving the fundamental issue - lack of supply due to various interest groups resisting supply growth.
https://www.brookings.edu/blog/the-avenue/2022/03/31/where-p...
https://noahpinion.substack.com/p/the-yimbys-are-starting-to...
Limiting large investors does not solve the problem, but it could help alleviate some acute symptoms.