I am forming a company that does stock market and real estate investment. Since its just a startup I have a basic accounting question: Lets say I spend $10000 to buy a stock and later in the year sell it for $12000. Is this correct to say the company revenue is $12000, with $10000 classified as cost and $2000 as profit?

With stocks and real estate it is a $2000 capital gain. You cannot expense capital investments