The seven factor categories
Each subject is scored across seven categories. Higher is safer (0 = critical, 100 = strong).
Each category decomposes into named sub-factors — for example, the smart-contract category is built from audit score, code age, formal verification, and code complexity; the oracle category from source redundancy, latency risk, manipulation resistance, and coverage. The full sub-factor set is the input layer the model scores against.
How factors become a score
The composite score is a weighted sum of the seven category scores:Explainability: factor attribution
Every score is accompanied by an attribution that decomposes the composite into per-factor contributions, so you can answer “why did this score move?” without guessing. The attribution uses Shapley values — the game-theoretic method for fairly dividing a result among the inputs that produced it. Because the model has exactly seven factors, Alterscope computes the exact Shapley value over all2⁷ = 128 factor coalitions rather than an approximation:
φᵢ is factor i’s contribution, S ranges over subsets of the other factors, and v(·) is the scoring function evaluated with the absent factors held at a neutral baseline. The attributions satisfy the efficiency property: they sum exactly to the score’s deviation from the neutral baseline, so nothing is unexplained.
These are Shapley values over Alterscope’s deterministic scoring function — they explain how each factor moved the composite away from a neutral baseline. They are not feature-importances from a trained black-box model; the scoring function itself is transparent.
Stability: covariance and hierarchical risk parity
Factor scores co-move — a liquidity shock and a market shock are not independent. To weight factors sensibly, Alterscope estimates how they move together and re-balances accordingly, using two methods drawn from quantitative portfolio risk.EWMA covariance
The factor covariance matrix is estimated with an exponentially-weighted moving average, which gives recent observations more weight than old ones:rₜ is the vector of factor changes at time t and λ is the decay parameter. λ is calibrated internally (it differs by asset class and is tuned to the volatility regime); we publish the recursion, not the tuned value. The covariance is refreshed on a regular schedule and converted to a correlation matrix and a distance matrix (d = √(½(1 − ρ)), after López de Prado) for the clustering step below.
Hierarchical risk parity (HRP)
Rather than inverting a noisy covariance matrix directly (which is unstable), Alterscope applies Hierarchical Risk Parity (López de Prado) to re-balance the factor weights. HRP runs in three stages:- Tree clustering — group factors by how closely they co-move, using the correlation-distance matrix.
- Quasi-diagonalization — reorder the matrix so similar factors sit together.
- Recursive bisection — split the tree top-down and allocate weight by inverse variance, so volatile clusters get less weight.
Model validation: the Deflated Sharpe Ratio
When Alterscope evaluates a risk model or strategy on historical data, it guards against backtest overfitting — the trap of a result that looks good only because many variants were tried. The check is the Deflated Sharpe Ratio (DSR) of Bailey & López de Prado:SR is discounted by the expected maximum Sharpe you would see by chance given the number of trials and the estimate’s own standard error:
“DSR” here is the Deflated Sharpe Ratio, an overfitting / multiple-testing correction. It is a model-validation tool, not a live risk score on a position.