Care to speculate on what might fit the bill?
1) Large investors are skid-dish due to the regulatory fog we are currently in. They need to KNOW that the rug won't be pulled out from under bitcoin. Basically, bitcoin needs to gain legitimacy and the current 'guidance' hasn't really helped.
2) A fund that lets people make payroll deductions to 'Invest' in bitcoin would do a lot to add stability / upward pressure to the market. The fund would actually have to purchase the bitcoins and hold them in proxy for this to work. I know that I would personally divert a portion of my payroll deductions towards this fund even if I wouldn't have access to the coins for a period of time.