ignirtoq

“Calls” and “puts” are types of contracts about buying/selling stocks (they aren’t the stock themselves but are centered around a given stock and its trading price, so they are called “derivatives” as they are “derived” from the stock).

A put is a contract that allows the buyer of the contract to sell stock at an agreed upon price to the seller of the contract, regardless of the current trading price. They are used for a variety of reasons. In one usage, someone who is buying some of the stock at the current trading price may also buy a “put” on the stock at a slightly lower price. This way, they spend a little more money at the time of buying the stock, but if the trading price plummets, they can still sell it at that slightly lower “put” price and not lose too much money.

In this case, the idea would be to buy a “put” (without buying the stock at the same time) when the buyer thinks the stock’s trading price is overvalued. Then when the price falls below the “puts” agreed upon value, buy the stock at the lower price and immediately invoke the contract to sell at the "put"s higher price.

The way posts are shared between instances is by user subscription. For example, if there’s a community on Lemmy and a Kbin user subscribes to it, Kbin will then receive new posts from that Lemmy instance for that community.

So if no one on an instance is subscribed to that community, new posts won’t flow to that instance. And then if you do subscribe to it, the instance will only automatically receive new posts. Federation will not back-fill older content.

You can click the hamburger menu icon (the 3 horizontal lines) on the very upper left of the page and it will open the sidebar overtop of the current view. Then you can scroll down just a little and find the send message button.