Obtain All Tickers Traded on BATS Exchange

This function downloads the public CSV file of all ticker symbols traded on the BATS exchange (list changed at least daily). This can be reconciled against a reference date/time, in which case change the timezone (mine is central time, as coded). Most of the time probably just don't supply any inputs or strip out the code relating to date/time.
The tickers are then scraped from the CSV file and reformatted for Yahoo Finance, but this can easily be recoded if some other data supplier is being used. This is just about the most comprehensive list of tickers available in a public format.