Because the size of the market was/is so small that you're actually able to corner it. Oil or Treasury futures are far too big that no single person could ever corner it.

Though the Hunt brothers made a pretty good run at the Silver market in 1980.

China went all in on rare earth concentrate processing, taking the environmental hits that no one else wanted to touch.

That paid off in a concentrated lock on the bulk of rare earth applications.

> Treasury futures are far too big that no single person could ever corner it.

Well, you'd think, but squeezing the CTD bond was completely accepted practice well into the noughties until PIMCO flew too close to the sun and faced regulatory wrath.

There are many other small markets as well, and yet, this law is not called the "Don't Corner Small Markets Act".

This came from the times when Congress wasn't deadlocked. If someone cornered a different small market they could make another law against that.

The point is that it's silly that the law is specific to onions, and the explanation "it's because onion market was small enough to be cornered" is unsatisfactory because there are other small markets too

Just like solving math or programming in a general sense is much harder than a specific solution , so is passing a broader law.

We don’t complain about switch cases in code when there is two or three switches we start refactoring once it starts to proliferate.

The law is no different , passing a wider ban would not get the votes easily or quickly and the interested parties the onion industry have no reason to push for it neither does the lawmaker acting on their interests.

If said small markets also had exceptions passed seeing the onion one there could have been case to be broad.

It would premature optimization to otherwise, based on just need for elegance , code or law has to work first even if dirty .