Each of the investors, Mohammed bin Ibrahim al-Issa and Mohammed bin Salah al-Rushudi, were fined 100,000 riyals ($26,700), the Financial Times reports.
The CMA accused Mr al-Issa of using his position on the board of Saudi Hotels to obtain privileged information, which he then used to trade on the company's shares.
In addition to his fine, he was banned for working for a listed company for three years and must pay back 3.37 million riyals in profits earned from the deal.
Mr al-Rushudi, meanwhile, was alleged to have used non-public information gained during his chairmanship of the Al Gassim Agricultural Company to illegally trade its shares.
Both men had denied the charges, the Financial Times noted.
Economist and head of research at Shuaa Caital, Mahdi Mattar, told the newspaper the actions were a "positive move" towards greater market transparency in Saudi Arabia.
Founded in 2004, the CMA reports directly to Saudi Arabia's head of state and prime minister King Abdullah Bin-Abd-al-Aziz Al Saud.