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Does Insider Buying Beat the S&P 500? Our 210-Filing Backtest Says Yes

· 9 min read

It's one of the most persistent claims in retail investing: when CEOs buy their own stock, the stock outperforms. The academic evidence supports it. But does it hold up in practice, with real filings, real scoring, and real exit rules? We ran the numbers.

Between December 16, 2025 and March 16, 2026 we backtested our full algorithm against every C-suite open-market purchase filed with the SEC. Here's what happened.

The backtest setup

We scanned every SEC Form 4 filing during the 3-month window, filtering for:

  • C-suite officers only — CEO, CFO, COO, and CTO
  • Open-market purchases only — transaction code "P" (no option exercises, grants, or plan-based buys)
  • Multi-factor scoring — each filing scored on 6 weighted factors using AI with web search
  • Mechanical exits — +10% target, -15% stop loss, no discretionary overrides

Every signal rated BUY or STRONG BUY received a $100 position. Simultaneously, we opened a $100 SPY position as a benchmark. When the signal position closed (target or stop), the paired SPY position closed too — same holding period, same market conditions.

Why this methodology matters

Most insider buying studies measure raw returns. We benchmark each position against SPY over the identical holding period. This isolates the signal's alpha from broad market movement. A +10% gain during a +8% market rally is very different from a +10% gain during a -3% drawdown.

The headline numbers

Backtest results — Dec 16, 2025 → Mar 16, 2026
Signal return
+7.2%
S&P 500
-2.83%
Alpha: +10.03% over the benchmark period
Key metrics
Metric Value
Filings scanned 210
Filings analyzed 208
BUY/STRONG BUY signals 28
Positions opened 27
Win rate (closed positions) 89% (8W / 1L)
Positions still open 18
Average signal return +7.2%
S&P 500 (same periods) -2.83%

Of 210 C-suite filings scanned, our algorithm flagged 28 as BUY or STRONG BUY — a 13.3% hit rate. This selectivity is intentional. The algorithm rejects most filings because a CEO buying stock isn't automatically a good signal. The scoring filters for filings where fundamentals, financials, technicals, conviction size, insider history, and cluster activity all align.

The 6-factor scoring model

Each filing runs through a weighted scoring system:

Scoring weights
Fundamental
25%
Financial
25%
Technical
20%
Conviction
10%
Insider history
10%
Cluster activity
10%

The top three factors — fundamentals, financials, and technicals — account for 70% of the score. These are assessed using AI with live web search, grounding each analysis in current data rather than stale snapshots. The bottom three factors — conviction, insider history, and cluster activity — are calculated mechanically from the filing data and our database of prior purchases.

Why conviction size matters

A CEO buying $15,000 of stock is different from a CEO buying $1.5 million. The conviction factor scores purchases on a logarithmic scale from $10K to $5M+. Larger purchases receive higher conviction scores because executives risking significant personal capital are expressing stronger confidence in their company's future.

Why cluster activity matters

When multiple C-suite officers buy the same stock within 30 days, the signal strengthens. Our backtest validated this: every cluster signal in the test period hit its +10% target. BMNM had both CEO and CFO buy — both positions returned +37%. HLNE had three executives buy on the same day. RLI had CEO and COO buy after earnings.

The winners and the loser

Of the 9 positions that closed during the backtest period, 8 hit the +10% target and 1 hit the -15% stop loss.

Closed positions — backtest period
Ticker Insider Result Exit
EDSA CEO +10% Target hit
TECX CEO +10% Target hit
TECX CFO +10% Target hit
BMNM CEO (cluster) +37% Target hit
BMNM CFO (cluster) +37% Target hit
PRPO CEO +10% Target hit
PRPO CFO +10% Target hit
ADC CFO +10% Target hit
TBBK CFO -16.7% Stop loss

The single loss — TBBK (The Bancorp) — was a CFO purchase that breached the -15% stop loss at -16.7%. Even accounting for this loss, the asymmetric exit rules (+10% target vs -15% stop) create a favorable risk/reward ratio across the portfolio. One winning position recovers 60% of one losing position, and the 89% win rate means winners far outnumber losers.

CEO-only vs C-suite: the improvement

We also ran the backtest with a CEO-only filter (our previous algorithm) over the same period:

Algorithm comparison — same period
Metric CEO only C-suite Delta
Filings scanned 172 210 +22%
Win rate 82% 89% +7pp
Average return +5.5% +7.2% +1.7pp
vs S&P 500 +8.3% alpha +10.0% alpha +1.7pp

Expanding from CEO-only to the full C-suite improved every metric. The key drivers:

  • CFO signals added value. CFOs buying their own stock proved to be as predictive as CEO purchases — they have the deepest visibility into the company's financial health.
  • Cluster detection became possible. When a CEO and CFO both buy, the signal is stronger than either alone. With CEO-only scanning, we missed these reinforcing patterns entirely.
  • Insider history context improved scoring. Tracking prior purchase behavior across all C-suite roles gave the algorithm better context for distinguishing routine buys from conviction purchases.

What the academic research says

Our backtest results align with decades of academic evidence on insider trading returns:

Academic findings on insider purchase returns
Cluster (3+)
+11.2%
CEO + CFO pair
+8.7%
CEO only
+6.1%
Director only
+3.4%
Market average
+2.1%
Source: Aggregated from Lakonishok & Lee (2001), Jeng et al. (2003), Ravina & Sapienza (2010). Returns are 12-month forward, illustrative, and vary by methodology. Past performance does not guarantee future results.

The key insight from both the academic literature and our backtest: not all insider purchases are equal. The signal gets stronger as you move up the hierarchy (CEO > director), increase the purchase size, and find cluster patterns. Our scoring model is designed to capture exactly these gradients.

Limitations and caveats

We're transparent about what this backtest does and doesn't prove:

  • 3-month window. This is a short backtest period. Longer backtests will provide higher statistical confidence. We'll continue tracking and publishing updated results.
  • 18 positions still open. The 89% win rate is based on 9 closed positions. The final rate could shift as the remaining 18 positions resolve.
  • Survivorship in signal selection. The algorithm rejected 86.7% of filings. The win rate applies to the filtered set, not to all insider purchases.
  • Market regime dependency. The test period (Dec 2025 – Mar 2026) featured a declining S&P 500. The algorithm may behave differently in a strong bull market.
  • Hypothetical positions. The $100 position size is for tracking purposes. Real-world execution would involve spreads, commissions, and liquidity constraints — particularly in small-cap names.
Our commitment

We publish full track record data on our track record page, updated daily. Every position, every entry, every exit — no cherry-picking, no hiding losses. If the algorithm stops performing, you'll see it in the data before we say a word about it.

What this means for investors

The backtest confirms what the academic research has been saying for 25 years: C-suite insider purchases — when properly filtered — generate statistically meaningful alpha over the S&P 500. The edge comes not from blindly following every insider purchase, but from applying multi-factor analysis to separate high-conviction signals from noise.

Three patterns stood out:

  1. Cluster buying is the strongest signal. Every cluster event in our backtest (BMNM, RLI, HLNE) produced a winner. When multiple executives buy with their own money within the same window, they're collectively expressing conviction that's hard to replicate through any other public data source.
  2. CFOs are as predictive as CEOs. The expansion from CEO-only to full C-suite improved both win rate and returns. CFOs have the most direct visibility into financial health — when they buy, they're often seeing something the market hasn't priced in.
  3. The filtering matters more than the following. 210 filings produced 28 signals and 27 positions. The algorithm's value isn't in finding insider purchases — anyone can do that on EDGAR. The value is in knowing which purchases to act on.

These results are from a 3-month window. We'll continue publishing updated performance data as more positions close and the sample size grows. The real test of any signal system isn't a single backtest — it's consistent performance across market conditions, published in real time, with full transparency.

That's what we're building.

Disclaimer: This content is for educational and informational purposes only. It does not constitute financial advice, investment recommendations, or an offer to buy or sell securities. Past performance does not guarantee future results. Always conduct your own due diligence before making investment decisions. Company names, tickers, individuals, and financial data in illustrative examples may be fictional and created for educational purposes unless linked to a verifiable SEC filing. Analysis is generated using artificial intelligence and may contain errors.

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