No points for guessing RP just because you were wondering what the mysterious RP is.
Spiders are a new idea in investing that has proven immensely popular.
Technically a Unit Investment Trust , for practical purposes they provide an alternative to an index fund for individual investors. The American Stock Exchange creates units of SPDRs by purchasing the underlying stocks in the proper proportions so that the value of each unit mimics the index, not perfectly but darn close. Well, we can't get away from it. Right now SPDRs are beating our beloved Foolish Four, and last year they beat both the Foolish Four and the RP variation. Now, I don't think that this is any kind of death knell for Dow investing strategies.