It wouldn't work if we put social security into stock market and investment because we had market stock crash before, especially in late 1920's until 1940's and again in 1987 so social security will running out of fund after financial crisis in 2008 and would leading to loan needed to fund the SS.
I already know about SS is dependent on workers that pay to retired Americans, also there is 401k but useless for people who work at minimum wage, including me and couldn't afford to put my money in 401k because need pay my living expenses. I think about should be other mandatory pension, that where all workers should to pay pension (worker based) depends on their income like minimum wage workers should pay 5% of their pension, that what I think about UK, Canada and some part of EU has one so I need ask Canadians/EU members to confirm about understanding of pensions because I just found out from UK/Canada members in other forum in few years ago.
In other way, I support reform the SS, not privatization because I don't trust them to put SS in stock market, even I noticed about 401k has went down during financial crisis, even happened to my mother and she lost several thousands in 401k. It would be increase SS tax, increase retirement age, adopt UK/EU style tax system, that what I know about many Americans don't want so adopt UK/EU style tax system is out of range but just suggestion, tackle the SS fraud if still issue like Medicare did. I can't believe about our government haven't fix the Medicare fraud that caused lost over billion dollars or rid of SS/Medicare but I wouldn't support rid of SS/Medicare because I need SS (SSI) to survive due college student and unable to work.
I'm personally believe that US will be face other financial crisis eventually because our politicians don't get along nor agree about fiscal and budget, it is obviously about both of GOP and Dem are party of nowhere, IMO.