fix: improve portfolio value calculation and round shares to six decimal places

src/app/api/funds/[slug]/invest/route.ts

@@ -45,12 +45,12 @@ export async function POST(req: NextRequest, { params }: { params: { slug: strin
   const portfolioValue = fund.user.positions.reduce((sum, p) => {
     const val = p.positionType === 'LONG'
       ? p.shares * p.hashtag.currentPrice
-      : p.avgBuyPrice * p.shares - (p.hashtag.currentPrice - p.avgBuyPrice) * p.shares
+      : (2 * p.avgBuyPrice - p.hashtag.currentPrice) * p.shares
     return sum + val
   }, 0)
   const totalValue = fund.user.balance + portfolioValue
   const nav = calcFundNav(totalValue, fund.sharesOutstanding)
-  const sharesToMint = amount / nav
+  const sharesToMint = Math.round((amount / nav) * 1e6) / 1e6
 
   // Weighted average NAV at buy for display
   const existingInvestment = await prisma.fundInvestment.findUnique({

src/app/api/funds/[slug]/redeem/route.ts

@@ -45,7 +45,7 @@ export async function POST(req: NextRequest, { params }: { params: { slug: strin
   const portfolioValue = fund.user.positions.reduce((sum, p) => {
     const val = p.positionType === 'LONG'
       ? p.shares * p.hashtag.currentPrice
-      : p.avgBuyPrice * p.shares - (p.hashtag.currentPrice - p.avgBuyPrice) * p.shares
+      : (2 * p.avgBuyPrice - p.hashtag.currentPrice) * p.shares
     return sum + val
   }, 0)
   const totalValue = fund.user.balance + portfolioValue
@@ -56,7 +56,7 @@ export async function POST(req: NextRequest, { params }: { params: { slug: strin
     return NextResponse.json({ error: 'Fund has insufficient cash to redeem. Try a smaller amount.' }, { status: 400 })
   }
 
-  const remainingShares = investment.shares - sharesToRedeem
+  const remainingShares = Math.round((investment.shares - sharesToRedeem) * 1e6) / 1e6
 
   const [updatedInvestor] = await prisma.$transaction([
     // Return cash to investor