The equal-weight S&P 500 fund is down 4.6% in a month the S&P 500 fund gained 0.9%

Over the past month, including dividends, ASPY, the fund that holds the S&P 500, is up 0.9%, while BRSP, which gives each of those stocks the same weight, is down 4.6%. The two funds are 5.5 percentage points apart.

Of 5,839 common stocks on the New York Stock Exchange, Nasdaq and NYSE American, 48.7% rose on Friday.

ASPY still gained 0.54%, and more than half of that gain came from Microsoft, up 3.7%, and Apple, up 1.5%. Nvidia, the largest holding, rose 0.2%, too small a move to account for the rise. Meta, another large holding, fell 3.3% and worked against the gain. BRSP gained 0.40%, 0.14 percentage points behind ASPY.

Nvidia is up 7.5% over that month, and Apple, the second-largest holding in ASPY, is up 8.8%. Those gains were not enough to keep BRSP from falling, because the fund holds each of them at the same size as every other stock it owns. AIWM, the fund that tracks the Russell 2000 index of small US companies, is down 5.4% over the same month.

The month's gap was already open before Friday. Over the past five sessions, including dividends, ASPY rose 1.3% and BRSP fell 0.2%. On Thursday, ASPY was down 0.08% and BRSP fell 0.50%.

On Monday, Jason Goepfert, founder of SentimenTrader, said he had not seen this in almost 100 years: the S&P 500 up at least 1% and within 1% of a high, with more of its stocks at new lows than at new highs. The only other days he named were July 23, 1929 and December 21, 1999. On Wednesday, Matt Phillips wrote that this is one measure among others. The share of S&P 500 stocks above their 200-day average, a running average of the past 200 closes, has weakened recently, he said, but not to a particularly severe level.

Whether Monday belongs with those two dates is their argument. A holder does not need that debate to know which result they got. The two funds already show it.