Buoyancy. That is what this indefatigable equity market has come to be known for over a four month stretch that has failed to yield a decline of at least 1% for either the S&P 500 or the Dow Jones Industrial Average. That is 102 trading sessions dating back to Oct. 11.

Put another way, Wall Street investors have gone through Halloween, a stunning election victory, weeks of shock, Veterans Day, Thanksgiving, Christmas, Hanukkah, New Years, Martin Luther King Jr. Day, Valentine’s Day, Presidents Day, four ballistic-missile firings by North Korea a tumble in oil prices, with nary a 1% blip neither from the S&P 500 nor the Dow industrials.

Such a preternatural period of supernatant trade is bordering on insane, but it is also historic, marking the longest stretch of trading days without a 1% decline since Dec. 18, 1995 for the S&P 500 and the longest since Sept. 20, 1993, for the Dow, according to Dow Jones data.

Stock-equity benchmarks tend to decline at least once every six trading sessions, according to Salil Mehta, a graduate school finance professor, who has worked at Georgetown University and New York University.