> They don't have any useful mechanism to stop the sale of a share of stock
The SEC exists. As do many other mechanisms by which the government regulates direct and brokered securities trades and sales. You can make the case that some of those controls are poorly/ineffectively implemented, but you can’t claim that it’s not something the government routinely regulates, intervenes in, and sometimes prohibits outright.
Society has deemed it "ok" for a real estate transaction to take days or weeks to process and mountains of paperwork, probably because it is done so rarely in an average person's life. But stock trades are expected to be done quickly in minutes or even milliseconds with high frequency trading. It just isn't feasible to inject government paperwork in the middle of a transaction. Wall Street would revolt if they even tried.
Nah. Look up the SEC’s reporting requirements, specifically form 4. The paperwork requirement already exists.
https://www.sec.gov/files/forms-3-4-5.pdf
Here are Musk’s. https://www.secform4.com/insider-trading/1494730.htm