yawaramin
a day ago
Actually, the real legal insider trading is the trades that you _don’t_ place based on insider knowledge. Eg, if you know that the iPhone is years ahead of everything else and you happen to be holding Apple stock, then you won’t let whoever is managing your portfolio sell any of it when otherwise you may not have cared. There’s no way to prove illegality for _not_ placing a trade.
dumberquestions
a day ago
There should be a name for this cognitive bias, not accounting for what someone is not doing.
seanwilson
a day ago
https://en.wikipedia.org/wiki/Omission_bias probably? "Omission bias is the moral judgement in which people prefer omission (inaction) over commission (action), and tend to believe harm as a result of commission more negatively than harm as a result of omission."
thereader12
a day ago
It just isn't provable, I think it it is technically illegal.
enoint
a day ago
I think the law says evidence needs a purchase or sale. Relatedly, the failure to purchase is not evidence.
rendaw
a day ago
Holding stock knowing it might go up is illegal? I don't think that's technically illegal.
thereader12
a day ago
If you were going to sell but learned something non public, then letter of the law says you can't make a decision to no longer sell.
cowlevel
a day ago
*because of insider knowledge
chii
a day ago
> if you know that the iPhone is years ahead of everything else and you happen to be holding Apple stock, then you won’t let whoever is managing your portfolio sell any of it
This is what executives with stock based compensations can an usually do.
we only regulate the sell side (or buy side), but not the inaction side (where you hold your existing position). I have not thought of a good way to make the market aware of these choices, in a way that enables market efficiency.
lordnacho
a day ago
There's already hedge funds that scrape the insider selling data for the executives.
You can then build a statistical arbitrage alpha based on the difference between an ordinary amount of selling (conditioned on a bunch of stuff) and a lack of selling/accelerated selling.
Vaslo
a day ago
For the top execs of public companies you can see what their holdings and transactions are anytime you like. You can also easily see when they haven’t sold. Any advantage here is already mined by people that price stocks for a living unfortunately.
Now if you could see the buying and selling for the next level below them somehow, that would be a great advantage (and also very illegal).
disgruntledphd2
a day ago
> Now if you could see the buying and selling for the next level below them somehow, that would be a great advantage (and also very illegal).
You could probably estimate this if the company has a trading window for employees (which I think almost all of them do).
Sum up the exec sales, then use the previous accounting data to estimate shares held by employees, and then create an index based on what direction employee sales are trending.
Because RSU grants track level (sortof), then you might be able to get a good sense for this, even though there would be lots of noise.
Warning: not investment advice (though if you're taking investment advice from a random HNer then you're probably doomed anyway).