r2d2-c3po

'very little risk' - I think standard deviation of return on S&P is something like 15%-20%...I wouldn't define a strategy with a buffer of 2.7% very little risk when the standard deviation is that high...

They wouldn't have to buy it back immediately. Short sellers would borrow the stock from a long and pay a predetermined interest rate for however long they're borrowing it. They technically don't have to rebuy the stock unless they get margin called (if the collateral posted is no longer deemed sufficient for the counterparty to allow the borrowing position) or need to close out positions because of some risk tolerance threshold being met. Usually when this happens to a bunch of shorts at the same time they must all rebuy, driving prices higher, which is called a short squeeze, but it is usually determined by someone cutting losses on a short position or positive news coming out driving prices up.

Short sellers don't need Tesla to fail to make money. There's plenty of room between Tesla being worth 50-60 billion and Tesla being worth 0. 50-60 billion of market cap means that Tesla has to do some absolutely crazy things in the next few years in an increasingly competitive environment while they've struggled consistently to meet production targets in less competitive environments. They have some problems such as a convertible bond issue for almost one billion due in Feb'19 that only adds to the cash burn problems if they can't meet the $360 convertible price. Short sellers push a narrative because they want the price to go down, but they really only take the position because they think that the market has currently mispriced the firm and there is opportunity there. They're not inventing problems, they're pointing out that they're there (perhaps exaggerating, but that's for the people to identify if true or not with the money they put on longs/shorts for Tesla).

Hmm yes, my interest is that this sort of defender may be hard to identify purely from event driven stats, as stats mostly track actions done (tackles succeeded/attempted, interceptions made). A player such as Maldini wouldn't have shown up on lists sorted for tackles made, although he may have shown up on tackle success % or interceptions (not sure because I can't find a good source of data for his playing stats). Despite this, he has the reputation of being one of the best defenders to play the game. I'm just curious about what sort of metrics could identify a player such as Maldini.

Thanks! Appreciate your comments

Thanks! Also, what are some sources for stats that would be available for free online? I've looked at some 538 stuff, some Statsbomb stuff, whoscored, and football-data.

Do you have any recommendations for how a hobbyist can get more into the field? Someone who has a technical background, but works in a different field unrelated to sports at all. Any reading material to get familiar with some of the stats and metrics that are used in the industry?