Offer your thoughts or opinion on the input financial query or topic using your financial background.

What happens when they run out of letters?
NYSE started allowing four letter tickers around 2009.  NASDAQ allows 4-5 letter tickers.  I guess they'll keep increasing when / if needed.  Companies are allowed to change tickers, although there are costs.  Tickers in the US are assigned through a single entity.  Companies that are new need to take something that's open. http://www.wsj.com/articles/SB124296050986346159 I see that you're in Australia, but, since there aren't really that many options to deal with the problem that you mentioned, I'd guess that you'll ultimately do the same.  Not sure about how tickers are assigned there though.