Returns the effective (DCA-weighted) entry price for a signal.
Uses cost-weighted harmonic mean: effectivePrice = Σcost / Σ(cost/price)
This is the correct formula for fixed-dollar DCA positions where each entry
has its own cost (e.g. $100, $200, etc.).
When partial closes exist, iterates through all partials to maintain a running
effective price, then blends with any new DCA entries after the last partial:
partial[0]: effectivePrice = costBasisAtClose[0] / Σ(cost/price for entries[0..cnt[0]])
partial[j>0]: remainingCB = prev.costBasisAtClose * (1 - prev.percent/100)
oldCoins = remainingCB / prevEffPrice
blend with new entries between prev and curr partial
final: blend remaining position with entries added after last partial
Returns the effective (DCA-weighted) entry price for a signal.
Uses cost-weighted harmonic mean: effectivePrice = Σcost / Σ(cost/price) This is the correct formula for fixed-dollar DCA positions where each entry has its own cost (e.g. $100, $200, etc.).
When partial closes exist, iterates through all partials to maintain a running effective price, then blends with any new DCA entries after the last partial: