Hi:

Welcome to the Vanguard Diehard Forum!

I was wondering if anyone had a source for software or online tools that would enable a variety of asset allocation strategies (predominantly using mutual funds - passive and active) to be back tested.

Nearly every investment newsletter that we can buy  has an asset allocation strategy that worked beautifully when it was backtested.  Unfortunately, the vast majority of backtested strategies don't work going forward.  For example:

During the past 26 years, if you had purchased the  top performing newletter  each year you would have lost an average of -27.6% your second year.  If you had simply bought and held the Wilshire 5000 Total Stock Market Index during the same period you would have enjoyed a gain  of +12,6% 

Source: "Hulbert Financial Digest--January 2008 issue)

"Backtesting" can be dangerous to our financial health.

Best wishes.
Taylor