JON,

I'm starting to think that the value presented is not really the difference between what your stock is earning, verses what the S&P500 is making, but more like a fixed amount based on how long you have held the stock.

“% S&P 500” is the long-term change you would have gotten if you'd invested in the S&P 500 rather than whatever you really did invest in. This assumes that you invest the same amount of money in the S&P 500 as you did in your stocks or funds, and at the same dates. Since we don't know what time you bought your stocks, we just use the closing S&P 500 value from the previous day. Also, dividends from the S&P 500 stocks aren't included, but neither are the fees you'd pay if you invested in an index fund. (For more info, click on the Help link in the blue bar on the My Portfolio page.)

So, the number in this column should be pretty close to the "LT % Val Chg" figure for your VFINX. There are a number of differences between the S&P index and VFINX; as I just mentioned our S&P figure doesn't include dividends, and also VFINX has a small amount in cash at any given moment, invests some in S&P futures rather than the actual stocks, and so on, mostly due to the realities of having people add and remove cash from the fund.

Hope this helps! If not, post on the My Portfolio message board for a prompt reply.

Phil
TMFRadish