S&P 500 After Rapid 10% Gains: +17% Avg One-Year Return | Alex Krainer

Historical S&P 500 data shows that sharp 10% rallies over a 10-day span tend to exhibit strong follow-through. On average, returns have been approximately +0.6% after one week, +2.5% after one month, and +17% over the following year.

Rapid 10%+ bounces in the S&P 500 (weekly candles), 1980 to 2026.

A review of the weekly S&P 500 chart from 1980 to 2026 highlights multiple instances of these "rapid +10% bounces," marked by green and red arrows. In most cases, these moves were followed by continued upside, though there were notable exceptions—such as the period around 2000.

 

Alex Krainer argues that the current setup differs meaningfully from the 2000  episode. He notes the absence of broadly synchronized overbought conditions among megacap stocks today, and emphasizes that the more significant declines in 2000 occurred only after the index had already fallen below its 40-week moving average.
 

S&P 500 RSI readings above 70 have led to pullbacks in 8 of the last 10 cases over two years, with the other two resulting in flat consolidation. The daily chart (May 2024–April 2026) marks these signals with red arrows for pullbacks and one green arrow, alongside recent price action near 7,000. This suggests an 80% likelihood of a near-term pullback, though prior corrections since the 2025 rally have been relatively mild.

Reference:
Alex Krainer (April 16, 2026) - Rapid S&P 500 10% rallies in 10 days historically show strong follow-through. 

 

Jeffrey Hirsch notes that the S&P 500's 7.57% gain in the first 10 trading days of April 2026 ranks as the second-strongest start to April since 1950.

Gains averaged +10.8% for the rest of the year, with full-year returns positive in 91.7% of cases (+16.2% avg.).

Historically, such powerful early-April momentum has been a bullish signal: in 20 of 24 comparable cases (83.3%), the market delivered further gains over the remainder of the year, with an average advance of +10.8%. Full-year returns were positive in 22 of those 24 instances (91.7%), averaging +16.2%. Hirsch’s data also segments April starts into performance tiers, with 2026 firmly in the top group—where subsequent returns have consistently outpaced those seen in the middle and bottom tiers.