What it measures

Log of absolute value of price (prc).

Why it should work

A value signal from the cross-sectional asset-pricing literature (Open Source Asset Pricing).

Full Sharpe
0.05
Ann. Return (LS)
1.2%
Ann. Volatility
22.6%
Max Drawdown
-68.5%

Growth of $1 — long-short

Technology only · cap-weighted · 331 months

Technology only
Where the edge comes from
Long leg Sharpe
0.40
top bucket, long-only
Long leg ann. return
13.9%
the buyable side
Bottom bucket Sharpe
0.52
the basket we short
Bottom bucket ann. return
12.7%
lower ⇒ wider spread

The bottom-bucket figures are that basket’s ownreturn (a long position in what the strategy shorts) — not the short side’s P&L. Long-short return = long leg − bottom bucket, so a falling bottom bucket widens the spread.

Performance by period
train
val
test
Sharpe by split
Train ’00–’120.04
Val ’13–’180.47
Test ’19–’26-0.17
Test FF5 α (ann.)
2.4%
alpha vs Fama-French 5
Test FF5 α t-stat
0.31
not significant
Monthly turnover
22%
of the long leg, per rebalance

Source study

Blume and Husic · 1973

Journal of Finance

187 citations
View on Google Scholar

Worked example

Live inputs for a real holding

AAPL · July 2026
InputValue
closeunadj333.74
Formula
log(closeunadj)
Raw5.8104Signed (×−1)-5.8104

signed_value is the internal ranking value; only its cross-sectional rank matters. $-vs-$M unit mix means ratio magnitudes carry a constant offset and are not comparable to textbook levels.

Replication

How closely this rebuild tracks the published research

Replicable
Open Source Asset Pricing signalPrice
Correlation — full sample—
Correlation — test window—
Published t-stat2.90

The OSAP comparison is only computed for the all-stocks variant — switch to “All stocks” above to see how the rebuild tracks the published series.

Style tilt

Size × value map of the long leg

85 classified
Value
Blend
Growth
Large
Mid
Small
·
11%1
9%1
19%6
10%4
15%5
17%33
7%10
5%11

Share of long-leg capital by market cap × book-to-market, using terciles of the 421-name universe at July 2026. Rows: Large ≥ $8.9B, Small < $1.9B. Columns: Value ≥ 0.63, Growth < 0.38 B/M. The dot marks the capital-weighted centroid of the book — 45% toward Large, 46% toward Growth. +6% unclassified (14 missing size/value). Hypothetical holdings — descriptive, not realized P&L.

Tilt over time
Size tilt45% → Large
SmallLarge
Value ↔ growth tilt46% → Growth
ValueGrowth

Capital-weighted centroid of the long leg, December 1998 → July 2026; the right-hand end is the same value as the box’s dot. 85 names now. Hypothetical holdings — descriptive, not P&L.

Since publication

Did the edge survive the paper coming out?

published 1973
Entirely since publication
All 331 months of our record post-date the 1973 paper.
Sharpe 0.051.2% p.a.January 1999 – July 2026

There is no “before” to compare against — the predictor was already public when our data begins, so every month shown is out-of-sample relative to the original study.

Split at January of the year after the factor was published. The post-publication stretch IS genuinely out-of-sample relative to the original study -- the predictor was public by then -- so it speaks to whether the effect survived being known. Nothing is fitted here, so this is performance SINCE PUBLICATION, not validation of a model. Note the 'pre' side is our data before publication (our panel starts ~1999), NOT the study's original in-sample period, which usually ran decades earlier; a decay figure compares before-vs-after within our sample and is not a comparison against the published result.

Derivatives risk (Rule 18f-4)

Relative VaR against the designated reference portfolio — as implemented here

long-short

This assessment describes the research long-short construction — long the top bucket, short the bottom.

Governing rule
Rule 18f-4(c)(2)(i) relative VaR (exception unavailable)

This fund does NOT qualify for the limited-derivatives-user exception (100% of net assets vs <= 10% of net assets), so the relative VaR test governs. Note the inversion: a dollar-neutral long-short book suppresses the market risk the VaR ratio measures and so tends to pass it, while being barred from the exception by construction — what disqualifies the strategy is the exposure threshold, not the risk limit.

Limited derivatives user exceptionby construction

Rule 18f-4(c)(4): a fund whose derivatives exposure (gross notional, including the value of assets sold short) is <= 10% of net assets is excepted from the VaR tests and the full derivatives risk management program.

Does not qualify
Required
<= 10% of net assets
Exposure
100% of net assets
Margin
−90pp

No confidence interval: this follows from portfolio construction, not from an estimate.

Rule 18f-4(c)(2)(i): fund VaR at 99% over 20 trading days must not exceed 200% of the designated reference portfolio's VaR on the same basis.

Within the limit as implemented
Measured
1.3 (95% CI 0.8-1.5)
x reference VaR
Limit
2.00x
<= 2.00x reference VaR
Fund VaR
12.3%
99% / 20d
Reference
9.6%
FF5 market (mkt)

historical method · 331 monthly observations · about 3.3 in the 99% tail · paired percentile bootstrap over months

Same test, three estimators
historical
1.27x
within
parametric
1.53x
within
cornish fisher
1.27x
within · unreliable

The estimators differ materially in value but agree on the verdict. Historical and Gaussian fund VaR differ by 17%; both still land on the same side of the 2x limit.

Engineering approximation of SEC Rule 18f-4 for research display. Not a compliance opinion and not a determination that any fund is compliant. Hypothetical model portfolio, not a registered fund.

Consistency across eras

Is this record broadly durable, or one regime?

26 windows
Positive windows
58%
15 of 26 3-year windows made money
Worst window
-0.68
Sharpe, August 2023 – July 2026
January 1999July 2026
Median Sharpe
0.06
Dispersion
0.43
Best window
0.87

3-year rolling windows, stepping 1 year (26 windows). Dispersion is the spread of window Sharpes — higher means the record depends more on which era you look at.

Rules-based factors fit no parameters, so these windows are not out-of-sample tests and do not validate a fitted model. They show whether the factor's record is consistent across eras or driven by one regime.

Returns

Long-short is the research line; the long leg is what a long-only fund could hold

since January 1999
Trailing
PeriodLong-shortLong leg
1 yearcum.-12.6%5.3%
3 yearsp.a.-13.1%8.4%
5 yearsp.a.-14.9%0.7%
10 yearsp.a.-6.4%18.0%
Since inceptionp.a.-1.2%8.3%
Calendar years
YearLong-shortLong leg
20267 mo-8.5%2.4%
2025-9.7%5.1%
2024-13.8%20.0%
2023-7.0%48.1%
2022-12.7%-40.2%
2021-18.7%12.1%
202028.3%92.7%
2019-8.4%42.7%
20185.4%9.2%
2017-19.5%13.7%
201619.4%33.7%
20151.0%-1.5%
20142.1%20.3%
201338.9%62.9%
2012-16.5%-0.9%
2011-19.0%-16.8%
20108.5%25.6%
200916.3%77.8%
2008-10.8%-51.2%
2007-21.4%-5.3%
200615.2%21.8%
2005-6.1%-8.7%
2004-25.9%-24.5%
200381.5%124.5%
2002-21.4%-47.6%
200136.1%-7.7%
2000-13.4%-51.7%
199910.0%111.6%

Long-short is the research line (long the top bucket, short the bottom); the long leg alone is what a long-only fund could actually hold. Trailing figures run through July 2026: 1 year is a plain cumulative 12-month return (cum.), 3 years and longer are annualised (p.a.). Years marked with a month count are partial. These match the fact sheet’s tables by construction. Hypothetical backtest, gross of the placeholder expense ratio and trading costs — not investor results.

Methodology

Signal computed monthly from Sharadar point-in-time data, signed so higher = higher expected return. Restricted to the Technology sector, then sorted into quintiles within that sector. The virtual ETF is long the top bucket, short the bottom, cap-weighted, rebalanced monthly. FF5 alpha regresses the long-short on the Fama-French 5 factors.

Hypothetical research backtest. Not an offer, recommendation, or investment advice.