Add position market value estimator

market.go

@@ -131,20 +131,24 @@ func (m *Market) NoMidPrice() Cents {
 	return (m.NoBid + m.NoAsk) / 2
 }
 
-// EstimateReturn shows the estimated return for an open position.
-func (m *Market) EstimateReturn(p *MarketPosition) Cents {
+func (m *Market) MarketValue(p *MarketPosition) Cents {
 	if p == nil {
 		return 0
 	}
 
-	var posMarketValue Cents
-
 	if p.Position < 0 {
-		posMarketValue = Cents(p.Position) * m.NoMidPrice()
-		posMarketValue = -posMarketValue
-	} else {
-		posMarketValue = Cents(p.Position) * m.YesMidPrice()
+		return Cents(p.AbsPosition()) * m.NoMidPrice()
 	}
+	return Cents(p.AbsPosition()) * m.YesMidPrice()
+}
+
+// EstimateReturn shows the estimated return for an open position.
+func (m *Market) EstimateReturn(p *MarketPosition) Cents {
+	if p == nil {
+		return 0
+	}
+
+	posMarketValue := m.MarketValue(p)
 	costBasis := p.MarketExposure
 	return p.RealizedPnl - p.FeesPaid + (posMarketValue - costBasis)
 }

portfolio.go

@@ -3,6 +3,7 @@ package kalshi
 import (
 	"context"
 	"fmt"
+	"math"
 	"strings"
 	"time"
 
@@ -378,6 +379,13 @@ func (p *MarketPosition) AvgPrice() Cents {
 	return p.MarketExposure / Cents(p.Position)
 }
 
+func (p *MarketPosition) AbsPosition() int {
+	if p.Position < 0 {
+		return -p.Position
+	}
+	return p.Position
+}
+
 func (p *MarketPosition) String() string {
 	if p == nil {
 		return "N/A"
@@ -389,9 +397,14 @@ func (p *MarketPosition) String() string {
 			avgCost = -avgCost
 		}
 	}
+
+	posSign := "+"
+	if p.Position < 0 {
+		posSign = "-"
+	}
 	return fmt.Sprintf(
-		"n: %d (+%d)\texp:\t%v\tcost: %v\treal: %v\tfee: %v",
-		p.Position, p.RestingOrdersCount, p.MarketExposure, avgCost, p.RealizedPnl,
+		"n: %s%d (𝚫 %d)\texp:\t%v\tcost: %v\treal: %v\tfee: %v",
+		posSign, int(math.Abs(float64(p.Position))), p.RestingOrdersCount, p.MarketExposure, avgCost, p.RealizedPnl,
 		p.FeesPaid,
 	)
 }