According to Investopedia , "Melt Up" is defined as:
A dramatic and unexpected improvement in the investment performance of an asset class driven partly by a stampede of investors who don't want to miss out on its rise rather than by fundamental improvements in the economy. Gains created by a melt up are considered an unreliable indication of the direction the market is ultimately headed, and melt ups often precede melt downs. (Source: www.investopedia.com/terms/m/melt-up.asp)
In a new article at fn / Financial News, the headline is:
Morgan Stanley says the stock market melt-up is over
The article quotes Michael Wilson, chief US equity strategist at Morgan Stanley, as saying the following...
“We think January was the top for sentiment, if not prices, for the year. With volatility moving higher we think it will be difficult for institutional clients to gross up to or beyond the January peaks.”
That article, dated March 19, 2018 can be read at the following link...
https://www.fnlondon.com/articles/morgan-stanley-says-market-melt-up-is-over-20180319