The Difference between Speculators and Gamblers, from Sushil Kedia
To add to an already long list of differences between broadly who a speculator may be and who a gambler may be: the successful speculator generally leans onto the side of chance but an unsuccessful gambler is seeking chance to lean on his side.
Countless differences may exist and can be cited between who a speculator is and who a gambler is. When we cut it slightly finer, there are enough similarities between an amateur speculator and an amateur gambler. Same way, there are enough similarities between a professional speculator and a professional gambler.
To seek a generally acceptable set of common characteristics between successful gamblers and successful speculators, I often listen to "The Gambler " by Kenny Rogers [Youtube link].