On the right hand of this website we have an applet that lists the current(ish) prices of XCH, BTC and ETH. The Bitcoin and Ether pricing are easy enough to figure out but I have had some questions about where the pricing for Chia comes from. And that’s a good question that I don’t rightly know.
To display the prices there I am using a widget called “Crypto Price Widgets – CryptoWP” by Alex Mangini and I settled on that one because it seems to mess up my site less than most Crypto widgets. They use the CryptoCompareAPI to do lookups in real-time against the CyrptoCompare.com website from the server. Supposedly they only store a minimum of price data in my websites DB, which is honestly still probably too much for me and I will be looking into what that means and if there are any alternatives.
But I think the question really means “where does your API get its pricing information?” and that is a little bit tougher to answer. First, its going to be competitive information for any API provider on how they compile their data with the most accurate being particularly valuable. So CryptoCompare says that they look at real-time order information from a number of exchanges and sources. And for XCH that would be a small number of them.

If you check the above order book out you can see that information is coming in from a few exchanges here, primarily Huobi and OKex for the big ones, and that pricing is all over the place at any given moment. What they appear to be doing is just weighting out what they think is appropriate and delivering a real price somewhere in the middle. You can see at the top exactly which Exchanges they are currently using that support XCH/USDT trades.
For my purposes that is fine, but it does seem like a very loosey-goosey way of pricing out an exchange-traded asset. Basically what it means is that you should not rely on the right hand of my website for up to date pricing information and you should make sure to check the actual Exchange you use instead.