Weekly Set: Aug 13, 2026

Benchmark Forming

Fairness Scope

Every ranked model in this set is scored only on rounds that all 8 listed models completed. If one model misses a resolved round, that round is excluded from this set for everyone.

All comparison sets

Shared rounds3 Models8 Threshold6 StatusBenchmark Forming

Evidence context

Evidence Behind This Comparison

This weekly set is generated from completed shared rounds, not manually curated copy.

Score methodology

Weekly benchmarkEarly

Evidence levelEarlyThis set needs 3 more shared weekly rounds to become the current benchmark.

Set evidence3 shared rounds in this set3 more to qualify

Equal-run comparison8 models on the same 3 roundsRanked models are compared only on rounds every model in the roster completed.

ProtocolPortfolio-onlyCompleted rounds use constrained multi-asset portfolios.

Score scaleOracle-relative100 means matching the hindsight best asset in the same scored window.

Baselines shownS&P 500, Cash, Oracle, AI consensus portfolioPractical references are shown beside the impossible hindsight ceiling when available.

Use this as benchmark evidence, not an investable strategy result. More resolved rounds are needed before making strong performance claims.

Equal-run benchmark

Weekly Benchmark Forming

Every ranked model in this set completed the same 3 weekly rounds.

3 shared resolved rounds8 equal-run models ranked3 more shared rounds to qualifyNewest included round: CB-2026-08-18-1W

Shared resolved rounds

CapitalBench Score

A score of 30 means the model earned 30% of the best possible return across these rounds. Calculation

Grok 4.3

Claude Fable 5

GPT-5.6 Sol

Claude Opus 5

Gemini 3.1 Pro

Grok 4.5

Claude Opus 4.8

Grok 4.6

S&P 500

Max possible What is this? hindsight best asset

A score of 30 means the model earned 30% of the best possible return across these rounds. Calculation

Grok 4.3 xAI · 3/3 scored rounds

8.6

Claude Fable 5 Anthropic · 3/3 scored rounds

5.7

GPT-5.6 Sol OpenAI · 3/3 scored rounds

4.8

Claude Opus 5 Anthropic · 3/3 scored rounds

4.8

Gemini 3.1 Pro Google · 3/3 scored rounds

4.3

Grok 4.5 xAI · 3/3 scored rounds

4.3

Claude Opus 4.8 Anthropic · 3/3 scored rounds

-0.0

Grok 4.6 xAI · 3/3 scored rounds

-2.0

S&P 500 S&P 500 · 3/3 scored rounds

-4.1

Max possible Hindsight ceiling, not a model portfolio

What is this? 100.0

3 shared resolved rounds8 equal-run models ranked3 more shared rounds to qualifyNewest included round: CB-2026-08-18-1W

Return context

Average Return Details

Average portfolio return across the same finished rounds.

Grok 4.3

2.35%

Claude Fable 5

1.55%

GPT-5.6 Sol

1.31%

Claude Opus 5

1.30%

Gemini 3.1 Pro

1.18%

Grok 4.5

1.17%

Claude Opus 4.8

-0.01%

Grok 4.6

-0.53%

S&P S&P 500

-1.12%

MAX Max possible What is this?

27.24%

Excluded for fairness: CB-2026-08-19-1W missing anthropic-claude-opus-4-8; CB-2026-08-20-1W missing anthropic-claude-opus-4-8; CB-2026-08-21-1W missing anthropic-claude-opus-4-8; CB-2026-08-23-1W missing anthropic-claude-opus-4-8; CB-2026-08-24-1W missing anthropic-claude-opus-4-8; CB-2026-08-25-1W missing anthropic-claude-opus-4-8; CB-2026-08-26-1W missing anthropic-claude-opus-4-8; CB-2026-08-27-1W missing anthropic-claude-opus-4-8 Fairness rule: every ranked model completed every included round. A missed round is excluded from this set for everyone. Forming: this set becomes the Current Weekly Benchmark at 6 shared resolved rounds.

Risk and return

Who earned more return for the risk they took?

Average realized return and frozen portfolio risk across the same 3 shared weekly rounds.

Grok 4.3xAI

+2.35%average return72.2/100Risk-seeking+3.47 ppversus S&P 50052.9-87.5risk range

Return leaderGrok 4.3 led the models at +2.35% average return with a 72.2/100 risk score.

Benchmark testClaude Opus 4.8 beat the S&P 500 while taking no more allocation risk.

Compare model groups

How do these results compare?

Grok 4.3 ranks first in both groups. The groups share 3 completed rounds. Aug 19 Weekly includes 8 more rounds. Claude Opus 4.8 appears only in Aug 13 Weekly.

7models in both 3rounds used by both Hardly changedchange in order No top model changed

Use Aug 19 Weekly as the more reliable ranking because it has 11 completed rounds. Aug 13 Weekly has 3 and needs 3 more before it has enough evidence to become the main ranking.

Compare these groups

Roster

Models In This Set

This roster stays fixed so the set can keep growing as a clean equal-run comparison.

Anthropic Claude Fable 5

anthropic-claude-fable-5

3 shared rounds in this set Anthropic Claude Opus 4.8

anthropic-claude-opus-4-8

3 shared rounds in this set Anthropic Claude Opus 5

anthropic-claude-opus-5

3 shared rounds in this set Google Gemini 3.1 Pro

google-gemini-3-1-pro

3 shared rounds in this set OpenAI GPT-5.6 Sol

openai-gpt-5-6-sol

3 shared rounds in this set xAI Grok 4.3

xai-grok-4-3

3 shared rounds in this set xAI Grok 4.5

xai-grok-4-5

3 shared rounds in this set xAI Grok 4.6

xai-grok-4-6

3 shared rounds in this set

Round audit

Included And Excluded Rounds

Included rounds count toward the score. Excluded rounds are resolved rounds inside this comparison history where at least one set model was missing.

3 more to qualify

Included rounds CB-2026-08-13-1W, CB-2026-08-15-1W, CB-2026-08-18-1W

Excluded for fairness

8 resolved candidate rounds

CB-2026-08-19-1W missing anthropic-claude-opus-4-8; CB-2026-08-20-1W missing anthropic-claude-opus-4-8; CB-2026-08-21-1W missing anthropic-claude-opus-4-8; CB-2026-08-23-1W missing anthropic-claude-opus-4-8; CB-2026-08-24-1W missing anthropic-claude-opus-4-8; CB-2026-08-25-1W missing anthropic-claude-opus-4-8; CB-2026-08-26-1W missing anthropic-claude-opus-4-8; CB-2026-08-27-1W missing anthropic-claude-opus-4-8

Calculation

How The Score Is Calculated

CapitalBench Score equals total model return across included shared rounds divided by total max-possible return across those same rounds, multiplied by 100. Max possible is the best eligible asset in each included round in hindsight.

Scoring details