No unfortunately I don’t have data I can share, but on big market platforms the clients want to know market liquidity every 5ms. High Frequency Trading demands information about the liquidity (not transactions) of every consolidated limited order book (every ticker) at a ferocious rate, in order to execute arbitrage.

Every HFT client wants every limit order of every ticker available on every trading terminal, every 5ms. People pay a lot of money for these feeds and the feeds are all built on websockets.

Pro Tip: clients don’t poll the exchange. The solution to the traffic and scalability problem lies in the choice of database framework.

Financial markets are orders of magnitude more traffic than all of social media, equivalent to millions of Tweets/second. These are the people renting all the antenna slots at data centres and dropping $20m on superconducting lasers to get insane bandwidth at insane latency.

I might be able to dig something up to share next week.