n. The severe overheating of a market that causes prices to rise to unprecedented levels.
1999
You hear more or less serious arguments these days that earnings don't count, that interest rates are irrelevant, that the macro backdrop is a distraction. Otherwise erudite observers use the phrase "melt-up" in their analyses. Melt-up? It can't be a well thought-out market if it is represented by so unlikely an image.
1988 (earliest)
In the final analysis, we might find tactical asset allocation (with futures) creates futures-driven markets just as portfolio insurance did (in combination with index arbitrage). While the market was vulnerable to a "meltdown" in the summer of 1987, however, it might be vulnerable to a "meltup" in the period ahead when this tactical asset allocation tidal wave responds to signals to increase equity exposure.