There was a time when trading on an exchange, especially a commodities exchange, meant a physical exchange trading floor, which was often a loud, chaotic, high-energy environment that not a lot of people could have access to or even understand.
The world of investment at this time was shrouded in a lot of mystery, moved slower and was certainly a lot more exclusive.
Access to markets and opportunities at the time was determined by levels of intermediaries, and being able to quantify risk and reward was a tall order that could be deciphered by few true experts.