Every "market" breakdown on FX forums eventually gets to the same seven buckets - commodities, equities, forex, and a handful of money-market/derivative instruments underneath. Inside forex specifically there's a clean three-tier split worth keeping in mind: majors (USD against a big developed economy - EURUSD, GBPUSD, USDJPY etc), minors/crosses (two majors with the USD removed - EURGBP, EURJPY), and exotics (a major currency against a developing-economy one - USDTRY, USDZAR). Liquidity drops and spreads widen as you move from majors to exotics, which is well known.
What gets skipped more often is the layer underneath all of it: almost nobody trading on MT4/MT5 is actually holding the underlying instrument. Retail forex/CFD accounts hold a contract for difference - an agreement with the broker to pay or receive the difference in price, where the broker is the counterparty, not an exchange. The price tracks the real market closely. The volume does not.
That matters a lot if you do anything volume-based - VSA, footprint reads, volume profile, absorption/exhaustion. On an exchange-traded future (say GC or 6E on CME), the printed volume is actual contracts changing hands through a central order book, cleared the same way for everyone. On a CFD/forex feed, "volume" is either missing, or it's tick count / your specific broker's own flow - not a consolidated market total. Two brokers quoting the identical EURUSD price can show two different volume histograms for the same bar, because they are not counting the same thing.
Practical takeaway: if you're testing a volume-based idea, the majors are the closest a CFD feed gets to matching real flow (deepest, most consolidated liquidity), and exotics are the worst match (thin underlying, broker's own book diverges more from the true market). And if you want volume to actually mean "contracts transacted at this price," you're better off looking at the futures contract on the same underlying rather than the CFD/spot version, since that is the only one with a real, exchange-cleared tape behind it.
Longer breakdown of the seven markets, the sub-categories inside each, and the CFD-vs-underlying distinction here if useful:
https://icf-market.net/education/fundamental-and-timing-analysis/global-markets-and-instrumentsLinkback: https://www.forex.zone/forex-education/29/cfd-vs-futures-same-price-on-both-but-only-one-has-real-volume/5133/
