Seasonal backtest · JPI Fair (balanced) method on the S&P 500 · 2015-2024 · Updated 2026-08-28
In short — historically (2015-2024, JPI Fair method on the S&P 500), buying in early March and holding 12 months returned +13.6%/yr on average — the 11th of the 12 months. $1000 would have become $3036 in 10 years (the S&P 500 index did +11.7%/yr on the same basis). Best month: May; worst: February. ⚠️ Only 10 years: a tendency, not a guarantee.
Below is the 12-month entry ranking (JPI Fair method, S&P 500, 2015-2024) — March is highlighted — then the year-by-year detail for buying in early March.
📖 How to read this table Method used: JPI Fair (the balanced formula — buy stocks where at least 2 analysts reliable on their sector are bullish, taking the median of their targets). Our recommended formula.
• Return / yr: average annual gain of that selection if you buy that month, over 2015-2024. • Ratio: return ÷ volatility — higher means steadier results (S&P 500 ≈ 0.9). • $1000 becomes (10y): what $1000 invested that month each year would become after 10 years (compounded). • S&P 500 comparison: the average S&P 500 return over the same period. It is far more stable regardless of the month (~14-18%/yr) — so the entry month matters mostly with the JPI method, not if you just buy the index.
📅 Why does the ranking stop at 2024? It's the window common to all 12 months. The 2025 cycles for August–December aren't finished yet (their 12 months haven't elapsed), so we exclude them from the ranking to compare every month on equal terms. Each month page, however, already shows its 2025 as soon as it's complete (January→July).
Year by year — buy early March
Year
Return (buy early March)
2026
+29.6% (ongoing)
2025
+23.5%
2024
+10.4%
2023
+16.5%
2022
-7%
2021
+18.5%
2020
+41.7%
2019
+4.4%
2018
+8.8%
2017
+26.6%
2016
+41.1%
2015
-25.5%
💡 Keep in mind: this comes from just 10 cycles. The robust research message is that staying invested beats waiting for a specific month. Use this ranking as an insightful curiosity, not a buy signal.
Over 2015-2024, buying in early March (JPI Fair method, S&P 500) returned +13.6%/yr on average, the 11th of the 12 months. But 10 years is little: it's a tendency, not a guarantee, and the entry month matters less than staying invested.
What would $1000 invested in March have become?
On average over 2015-2024, $1000 invested in early March each year (12-month hold, JPI Fair method) would have become about $3036, versus the S&P 500 index on the same basis.
What is the best month to invest compared to March?
In our 2015-2024 ranking, May comes first. March is the 11th. See the full 12-month ranking above.
What is JPI Invest?
JPI Invest aggregates analyst recommendations across the entire S&P 500 (plus the S&P MidCap 400), replays them against real prices and measures who predicts best — on results, not reputation. Instead of taking a price target at face value, you see each analyst's track record on each stock.
🏆 Analyst leaderboard by real reliability (beating their sector, not just riding the rally)
🎯 What to buy: 3 backtested methods over 6 years, from cautious to aggressive
💬 AI assistant: ask anything about any stock, with the numbers
⚠️ Educational analysis, not investment advice. Point-in-time backtest on recomputed Yahoo data, short sample (10 years). Past performance does not predict the future.