Posli forex so z razvojem informatike postali popularni tudi za majhne investitorje. Sprva je pojem forex označeval posle z valuto na medbančnem trgu. Danes se pod tem izrazom skrivajo vsi mogoči posli (dejanski promptni ali terminski posli in tudi denarne verige). Pri obravnavi posla forex je potrebno tako najprej ugotoviti, kakšno pogodbo sta stranki dejansko sklenili (torej za kakšne vrste posel gre). Za davčne in računovodske potrebe je tako nujno pridobiti status pogodbenih strank, vrsto instrumenta, s katerim sta stranki trgovali in predvsem vrsto trga, na kateri je bil posel sklenjen.

With the development of informatics, forex business has become very popular among retail and small investors. At the beginning, the term "forex" was used to denote the interbank currency market. Nowadays, however, different legal institutes (e.g. spot forex, forwards, futures, Ponzi schemes etc.) are covered by this term. Therefore, dealing with forex first requires the knowledge about the type of contract that the parties involved have actually concluded. For tax and financial purposes, at least: the status of the parties to the contract, the type of the financial instrument and, above all, the type of market on which the transaction was done, need to be discovered.