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Corbex Funds Management / Strategy White Paper

Preserve capital. Then grow.

Arbiter is designed to select 10 to 20 US-listed companies when market conditions are favorable, add defensive positions when market-wide risk rises, and restore exposure as conditions improve. We research, execute and monitor Arbiter daily.

Effective 30 September 2026 · Release arbiter-2026-09-04-research-r88

The architecture

  1. Gather and reconcile point-in-time company filings, earnings calls, institutional activity, analyst revisions, brokerage data, market structure, rates, volatility, and macroeconomic evidence in an owned research lake.
  2. Construct proprietary company, sector, and regime features with production data pipelines that preserve timing, provenance, and revision history.
  3. Run governed AI inside Corbex's fundamental-analysis harness using versioned prompts, fixed schemas, source citations, validation gates, and stability checks.
  4. Combine governed features through versioned machine-learning models, then apply explicit rules for ranking, concentration, sizing, and defensive exposure.
  5. Implement portfolio changes in highly liquid US-listed securities through opening-auction orders, then retain the complete research-to-production lineage for review.

Strategy characteristics

Core exposure
Concentrated US-listed growth equities
Typical long book
Approximately 10 to 20 companies
Defense
Broad-market or sector ETF shorts
Decision cycle
Daily research and manager-approved market-on-open execution

Methodology and assumptions

Decision cycle: Daily research and manager-approved market-on-open execution

Execution: Market-on-open portfolio rebalance timing.

Trading costs: 10 basis points per unit of turnover.

Financing costs: 75 basis points annualized for modeled ETF borrow exposure.

Benchmark: QQQ - Buy-and-hold total return with dividends reinvested (dividend-adjusted closes), rebased to $1.00 on 2018-01-09 and aligned to every Arbiter session through 2026-08-04. It provides a same-window US large-cap equity comparison and is not the index itself.

Data window: 2018-01-09 through 2026-08-04, covering 2,153 trading sessions.

Simulated returns reflect Market-on-open portfolio rebalance timing, 10 basis points per unit of turnover, and 75 basis points annualized for modeled ETF borrow exposure. No fund fee is applied in this simulation.

The research evidence

Historical simulation - frozen and reproducible

Same-window comparison · 2018-01-09 through 2026-08-04
MetricArbiterNASDAQ-100 Index Proxy
Annualized return34.35%19.87%
Sharpe ratio1.7180.877
Maximum drawdown-12.37%-35.12%
Maximum underwater142 sessions493 sessions
Ending growth of $1$12.46$4.70
Annualized volatility18.16%23.94%
Sortino ratio2.6571.249
Calmar ratio2.7770.566
Beta to benchmark0.4561.000
Correlation to benchmark0.6021.000
Positive sessions54.48%56.06%

NASDAQ-100 Index Proxy · QQQ ETF · Buy-and-hold total return with dividends reinvested (dividend-adjusted closes), rebased to $1.00 on 2018-01-09 and aligned to every Arbiter session through 2026-08-04. Sharpe ratios use a 0% risk-free rate. Annualized return compounds at 252 trading sessions per year. Sortino downside deviation uses a 0% target averaged over all sessions.

Historical simulation - frozen and reproducible

Growth of $1

Arbiter $12.46 | NASDAQ-100 Index Proxy $4.70

$0.9$1.7$3.4$6.6$12.920182026Arbiter $12.46 | NASDAQ-100 Index Proxy $4.70ArbiterNASDAQ-100 Index Proxy

Scroll horizontally to explore the full chart.

Monthly values · Log scale

Historical simulation - frozen and reproducible

Calendar-year compounding

Full calendar-year record for the tested period
PeriodArbiterNASDAQ-100 Index ProxyDifference vs NASDAQ-100
2018+1.85%-4.29%+6.14%
2019+12.69%+38.96%-26.27%
2020+75.03%+48.62%+26.42%
2021+65.74%+27.42%+38.32%
2022+14.10%-32.58%+46.68%
2023+34.18%+54.85%-20.68%
2024+39.76%+25.58%+14.19%
2025+36.14%+20.77%+15.38%
2026 through August 4+28.48%+17.98%+10.51%

Validation evidence

Selection-adjusted method

Bailey–López de Prado Deflated Sharpe Ratio - The Deflated Sharpe Ratio adjusts the selected complete-strategy Sharpe for the measured search family, sample length, cross-path dispersion, skewness, and kurtosis. It validates the complete strategy within the search family and does not independently validate the defensive overlay.

Strategy complexity

Complexity score: 5

ComponentRulesDescription
Stress signal1Aggregates the declared breadth-stress inputs into one bounded activation signal.
Cyclic controller2Uses a bounded active interval and a bounded inactive interval while the stress signal persists.
Funded defense action2Caps the liquid ETF short and funds it only from available defensive collateral.

Controlling for selection bias

The discovery program evaluated 183 candidate formulas across 169 distinct economic paths before this strategy was registered. Reporting the best result of a large search as if it were a single experiment is how backtests flatter themselves, so the record is judged with the Deflated Sharpe Ratio: the observed Sharpe ratio must clear a hurdle raised by the breadth of the search, the length of the record, and the non-normality of returns. Sharpe ratios use a 0% risk-free rate. Annualized return compounds at 252 trading sessions per year. Sortino downside deviation uses a 0% target averaged over all sessions.

The record clears that hurdle under every disclosed treatment - including the registered punitive treatment, which charges the entire search against the strategy.

ScenarioTrial treatmentObserved SharpeDeflated Sharpe probability
Registered punitiveAll 169 distinct economic paths independent1.64899.96%
Registered correlation adjustedAverage-correlation implied independent trials1.64899.98%
Selection punitiveAll 169 distinct economic paths independent1.73599.98%
Selection correlation adjustedAverage-correlation implied independent trials1.73599.99%

Validation windows

WindowDatesSessionsCAGRSharpeMaximum drawdownMaximum underwater
DiscoverySelection window for the registered simplified complete strategy within the frozen defense-formula family.2018-01-09–2022-12-301,25430.76%1.648-11.65%142 sessions
Reused extensionAlready inspected during final selection; descriptive continuation, not pristine out-of-sample evidence.2023-01-03–2026-08-0489939.51%1.810-12.37%117 sessions
Full recordCombined discovery and reused-extension record at the registered 10 bps trading-cost and 75 bps borrow frame.2018-01-09–2026-08-042,15334.35%1.718-12.37%142 sessions

Cost sensitivity

Cost frameCAGRSharpeMaximum drawdownCAGR / drawdownMaximum underwater
Gross frame · no trading or borrow costs41.51%2.006-11.51%3.605127 sessions
10 bps trading / 75 bps borrow · registered net frame34.35%1.718-12.37%2.777142 sessions
Gross frame · discovery window37.50%1.942-11.02%3.402127 sessions
10 bps trading / 75 bps borrow · discovery window30.76%1.648-11.65%2.640142 sessions

Overlay diagnostic

Does not pass 95% incremental DSR - The complete simplified strategy passes the stage-specific DSR within its immediate search family. The defensive overlay does not independently clear the 95% threshold; its case remains bounded risk logic, drawdown behavior, temporal diagnostics, and prospective observation rather than a standalone-alpha claim.

Limits

  • The 2023–2026 extension was already inspected during final strategy selection and is not a pristine out-of-sample holdout.
  • The complete-strategy DSR does not independently validate the defensive overlay or establish standalone defensive alpha.
  • The calculation covers the immediate 183-formula defense family and 169 distinct economic paths, not the full research lineage.
  • The frozen record does not include the 2 bps daily selection path; its scenarios conservatively reuse the registered discovery skewness and kurtosis with the reported 0.03491 selection-frame Sharpe dispersion.
  • Cost sensitivity is reported from the two published frames - the gross frame and the registered 10 bps trading / 75 bps borrow net frame - over the full record and the discovery window; intermediate cost levels are not separately simulated.
  • Results are gross of prospective investor fees, vehicle expenses, taxes, financing outside the declared borrow assumption, and other implementation differences.

What validation can and cannot prove

These tests establish that the simulated record is unlikely to be an artifact of search: the mechanics are frozen under cryptographic locks, the data is point-in-time, discovery and extension windows are reported separately, and the result survives punitive cost and selection treatments. Historical simulation cannot establish execution against real liquidity under real operations. We research, execute and monitor Arbiter daily. This research evidence does not establish live validation or promise future results.

Why this backtest is reproducible

The daily series is frozen, and every displayed statistic reproduces directly from it under a hash-checked release manifest. Results reflect the registered cost model - 10 basis points per unit of turnover and 75 basis points annual borrow. No fund fee is applied in this simulation. The Deflated Sharpe analysis charges the result for the measured search that produced it. Reproducibility of a historical simulation does not establish its implementation assumptions in live operation. We research, execute and monitor Arbiter daily.

Risk factors

  • Concentration can amplify company, factor, and sector losses.
  • A defensive sleeve can lag in sharp reversals or fail to offset long-book losses.
  • Research selection and reused historical windows can overstate robustness.
  • Live data, liquidity, financing, order timing, and implementation can differ from modeled assumptions.
  • Models and market relationships can degrade or fail under new regimes.

Important information

This document is part of a frozen product release and presents hypothetical performance for independent evaluation. It is not an offer to sell or a solicitation of an offer to buy any security.

Arbiter operates as a private fund currently focused on the Founder's and affiliated family capital. No interests are offered and no capital is solicited through this document.

Historical simulation applies today's strategy rules to past data. It benefits from hindsight, reflects no live execution, and cannot capture the market impact of actual trading. Simulated records routinely overstate what live implementation achieves. Sharpe ratios use a 0% risk-free rate. Annualized return compounds at 252 trading sessions per year. Sortino downside deviation uses a 0% target averaged over all sessions. Arbiter is a concentrated systematic equity strategy and can incur substantial loss. Model, data, execution, liquidity, short-exposure, market-regime, and implementation risks can cause actual outcomes to differ materially from research. Arbiter performance shown in this release is a historical simulation, frozen and reproducible directly from the daily return series and release manifest; it is not actual client performance and has not been independently audited or approved by a regulator. Benchmark means the QQQ ETF used as a total-return proxy (dividends reinvested) for the Nasdaq-100; QQQ is not the index itself. Arbiter's simulated returns exclude dividends on its long holdings while the benchmark includes them; the methodologies differ in this respect. Simulated results have inherent limitations. Past performance does not guarantee future results. We research, execute and monitor Arbiter daily. Account monitoring does not establish live validation of the strategy. Arbiter is currently focused on the Founder's and affiliated family capital; nothing in this release is an offer to sell or a solicitation of an offer to buy any security.

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