quite right - stocks have a centralized exchange; forex futures do; spot forex/CFD-forex doesn’t
reliably on the CME (futures volumes and DoM)
less reliably (but maybe good enough for some?) with a huge broker (maybe Oanda?) whose volumes/orders “should be” roughly proportional to those in a real market
when you “trade” with a spot forex broker, you’re not really trading at all - just betting against them on the price of their own “products”; no currencies actually change hands, and your “trades” are not in any “market” at all
none of the top 10 percent of traders that are trading say 5-10 positions of 50 lots is trading spot forex - take this literally, when I say “none” I mean not one - for the very simple reasons explained here and here
by trading futures instead of spot