I'm highly skeptical that heavily restricting buying and selling of companies in general will be a better way to run a market when it seems your goal is to prevent monopolies (or put another way, ensure competition).

Laser focused policies work for a short periods but tend to be worked around quickly as the thing they regulate falls out of favor in lieu of something functionally the same but different enough it doesn't match. Blanket policies tend to stifle the market in general, causing other problems. Rather than assuming that any specific law actually "solves" the problem, we'd probably be much better off setting criteria we're trying to match and and reassessing regulations regularly to try to meet that criteria. Anything unresponsive will be routed around.