Open ECry has a free sim. I think it runs for 2 weeks, but you can request an extension or pay a small fee per month to have it. The nice thing is that you will get an immense amount of data w/ that even if you end up paying for the sim. Most other platforms will require some data to run it - example - NinjaTrader is free to sim but you need data to plug into it. DTN is easily $100/mo for that. https://www.openecry.com/software/download1.cfm