# Polymarket Copy Trading: Following 30 Seconds Late Cost 1.43¢ a Share, Before Fees

Scope checked against the publication dated 25 October 2026.

Selected calculations checked in Lean. The empirical study is not formally proved.

Calculation and displayed-value checks:

- Matched, unmatched and set-aside buys partition the recorded leader buys (row 1). (`polymarket_copy_trading_costs_and_tools_1`; arithmetic).
- Matched, unmatched and set-aside buys partition the recorded leader buys (row 2). (`polymarket_copy_trading_costs_and_tools_2`; arithmetic).
- Matched, unmatched and set-aside buys partition the recorded leader buys (row 3). (`polymarket_copy_trading_costs_and_tools_3`; arithmetic).
- Matched, unmatched and set-aside buys partition the recorded leader buys (row 4). (`polymarket_copy_trading_costs_and_tools_4`; arithmetic).
- Matched, unmatched and set-aside buys partition the recorded leader buys (row 5). (`polymarket_copy_trading_costs_and_tools_5`; arithmetic).
- Matched, unmatched and set-aside buys partition the recorded leader buys (row 6). (`polymarket_copy_trading_costs_and_tools_6`; arithmetic).
- The illustrative entry, platform and slippage costs sum to the displayed total (column 1). (`polymarket_copy_trading_costs_and_tools_7`; arithmetic).
- The illustrative entry, platform and slippage costs sum to the displayed total (column 2). (`polymarket_copy_trading_costs_and_tools_8`; arithmetic).
- The illustrative entry, platform and slippage costs sum to the displayed total (column 3). (`polymarket_copy_trading_costs_and_tools_9`; arithmetic).
- Displayed Cost as share of stake values lie between 0 and 100 in section-the-three-costs-worked-chart. (`polymarket_copy_trading_costs_and_tools_10`; displayed-value-domain).
- Displayed Top 100 wallets values lie between 0 and 100 in section-the-best-wallets-are-the-most-expensive-to-follow-chart. (`polymarket_copy_trading_costs_and_tools_11`; displayed-value-domain).
- Displayed Wallets ranked 101 to 1,000 values lie between 0 and 100 in section-the-best-wallets-are-the-most-expensive-to-follow-chart. (`polymarket_copy_trading_costs_and_tools_12`; displayed-value-domain).


Outside the proof:

- Authenticity, completeness and accuracy of source observations.
- Data collection, sampling, classification, bootstrap intervals and causal inference.
- Current prices, policy, legal status, allegations, product claims and future outcomes.
- Production code correctness, execution, available liquidity and profitability.

[Machine-readable scope and exact input locations](polymarket-copy-trading-costs-and-tools.json). [Lean calculations](../LibraryChecks.lean). [Mathematical definitions](../ResearchModels.lean). [Verification record](../verification.json). [Complete package](../proofs.zip).

Body SHA-256: `f37d58842dd561eabf7f2ba06f4336d5feccce45c6f246b0711417a2cbabfa17`. Source observations are premises, not conclusions of the proofs.

25 Oct 2026: the body hash now leaves out the photograph block (image), as it already left out sources and updatedAt. The scope is unchanged. Previous body SHA-256: c9851fdec43ddfd989f12a90853e09c870411f1290a8dc7da7164a9d0f479318.