This answer, though somewhat dated, comes with the best credentials: "The question is still open experimentally, but theory and experiment are pointing more than ever before to the possibility that we have discovered the 'ultimate constituents'." — National Research Council (U.S.), Elementary-Particle Physics Panel (1998), Elementary-Particle Physics, National Academy Press, Washington, D.C., p. 23.

But are the "ultimate constituents" pointlike entities, or are they formless?