Stock Snapshot API will give you access to all U.S Market with one single API request. You can get the latest trades, quotes or both of them with one request.
* quotesEnable or disable last quotes. Default is true.
* tradesEnable or disable last trades. Default is false.
* symbolsYou can get the data from specific symbols by using this query. If you leave it empty, you will get the all available last data. (Separate symbols with commas.)