code: public long calculateStandardDeviationSquaredFemtos() {
          long totalFemtos = 0L;
          for (AssetClassAllocation a : assetClassAllocationList) {
              for (AssetClassAllocation b : assetClassAllocationList) {
                  if (a == b) {
                      totalFemtos += a.getQuantifiedStandardDeviationRiskMicros() * b.getQuantifiedStandardDeviationRiskMicros()
                              * 1000L;
                  } else {
                      // Matches twice: once for (A, B) and once for (B, A)
                      long correlationMillis = a.getAssetClass().getCorrelationMillisMap().get(b.getAssetClass());
                      totalFemtos += a.getQuantifiedStandardDeviationRiskMicros() * b.getQuantifiedStandardDeviationRiskMicros()
                              * correlationMillis;
                  }
              }
          }
          return totalFemtos;
      }
docs: Not incremental.