zlacker

The short answer: What exactly the "price" shown on the exchange website is depends on the exchange. Typically it's the last trade price or the mid price (average of best bid and offer). There really is no such thing as a single "price" because the price will depend on the quantity and direction you are transacting in.

Long answer: You need to understand how the Limit Order Book works. I wrote up something about this here [1]. It also goes into different definitions of price.

> If a very low-volume stock is listed at $4, and then I offer to buy a share for $100, does the NYSE suddenly start listing its price at $100?

If you trade actually absorbs the order book and pushes the asks to $100 then yes, that could be case depending on the exchange, but I'm not sure about NYSE specifically. Most likely that could never happen due to various hidden order types and HFT market makers though.

[1] https://www.tradientblog.com/2020/03/understanding-the-limit...

>>traK6D+(OP)
Thank you! So each exchange has its own formula for determining the price that gets shown on the ticker?

Let's say someone owns shares in a very low-volume stock — one that gets a couple trades a day, at most. Could they artificially increase the share price by offering their shares at a high price, then using a second account under their control to immediately buy them at the inflated price?

>>robert+3p
Yes, this is called cross-trading [0] and AFAIK is forbidden by the SEC.

[0] https://www.risk.net/definition/cross-trade