  We report optical, infrared, and X-ray light curves for the outburst, in
2000, of the black hole candidate XTE J1550-564. We find that the start of the
outburst in the H and V bands precedes that seen in the RXTE All Sky Monitor by
11.5 +/- 0.9 and 8.8 +/- 0.6 days, respectively; a similar delay has been
observed in two other systems. About 50 days after the primary maxima in the
VIH light curves, we find secondary maxima, most prominently in H. This
secondary peak is absent in the X-ray light curve, but coincides with a
transition to the low/hard state. We suggest that this secondary peak may be
due to non-thermal emission associated with the formation of a jet.
