So unless I become a high-risk day-trader, there really is no way for me to make a living just investing in the stock market?
So did people like Warren Buffet and Morgan Stanley build their wealth some other way? And what about the fictional character Gordon Gecko?
Your question doesn't make clear whether you want to "make a living" investing other people's money, or your own. Both are possible. I already gave you a reference regarding careers in the financial advisory and brokerage business. It is also possible to live on the income and capital gains from your own investments, if you save enough while young to make this possible, look for value and diversify to avoid major losses when times are tough. Don't look for hot stocks and funds to make you rich in a few years.
Gordon Gecko may be fictional, but there are over a million Americans in the business of giving financial advice, acting as stock brokers or managing assets. Sometimes it is a hot business to be in, but in hard times jobs can be insecure.