@lacspace/market

The money & mechanics toolkit every stock-market app re-implements — including a real Indian brokerage & charges calculator.

P&L, returns, CAGR, XIRR, tick-size rounding, circuit limits, risk-based position sizing — plus the thing nobody packages: a full Indian brokerage & statutory charges breakdown (STT, GST, SEBI, stamp duty, exchange txn) with discount-broker presets.

• 💸 Charges calculator — the exact Zerodha-style breakdown traders actually see
• 📊 P&L, changePercent, pnlPercent, cagr, xirr, averagePrice
• 🎯 positionSize (risk-based), roundToTick, circuitLimits
• 🇮🇳 formatINR with lakh/crore grouping
• ⚡ Zero dependencies · 🌍 isomorphic · 📦 ESM + CJS · fully typed

Install

npm install @lacspace/market      # or pnpm add / yarn add / bun add

The charges calculator ✨

import { charges } from "@lacspace/market";

charges({ segment: "intraday", buy: 100, sell: 102, qty: 500 });
// {
//   turnover: 101000, brokerage: 30.3, stt: 12.75, exchangeTxn: 3,
//   sebi: 0.1, stamp: 1.5, gst: 6.01, dp: 0,
//   totalCharges: 53.66, grossPnl: 1000, netPnl: 946.34, breakeven: 0.11
// }

charges({ segment: "delivery", buy: 1000, sell: 1100, qty: 10 });
charges({ segment: "options", buy: 120, sell: 150, qty: 75 });

Rates default to an Indian discount broker (Zerodha-style, FY2024–25). Statutory rates change — override any field and always verify against the live rate card:

import { charges, IN_DISCOUNT_BROKER } from "@lacspace/market";

charges(input, {
  ...IN_DISCOUNT_BROKER,
  segments: {
    ...IN_DISCOUNT_BROKER.segments,
    delivery: { ...IN_DISCOUNT_BROKER.segments.delivery, brokeragePct: 0.001 },
  },
});

Returns & P&L

import { pnl, pnlPercent, changePercent, cagr, xirr } from "@lacspace/market";

pnl({ buy: 100, sell: 112, qty: 50 });   // 600
pnlPercent({ buy: 100, sell: 112 });     // 12
changePercent(2950, 2900);               // 1.72  (LTP vs prev close)
cagr(100000, 200000, 3);                 // 0.2599  (25.99% a year)

xirr([
  { amount: -10000, date: "2024-01-01" },
  { amount: -5000,  date: "2024-06-01" },
  { amount: 17000,  date: "2025-01-01" },
]); // ≈ annualised return, irregular cash flows

Trade mechanics

import { averagePrice, positionSize, roundToTick, circuitLimits, formatINR } from "@lacspace/market";

averagePrice([{ price: 100, qty: 10 }, { price: 110, qty: 10 }]); // 105
positionSize({ capital: 100000, riskPercent: 1, entry: 500, stop: 480 }); // 50 shares
roundToTick(101.23);            // 101.25  (nearest ₹0.05)
circuitLimits(100, 10);         // { upper: 110, lower: 90 }
formatINR(1234567.5);           // "₹12,34,567.50"

API

| Function | Description | | --- | --- | | charges(input, config?) | full brokerage + statutory breakdown | | pnl / pnlPercent / changePercent | profit & loss | | cagr(begin, end, years) | compound annual growth rate | | xirr(cashflows, guess?) | irregular-cashflow annualised return | | averagePrice(trades) | volume-weighted average | | positionSize({...}) | risk-based whole-share sizing | | roundToTick(price, tick?) | snap to exchange tick | | circuitLimits(prevClose, %) | upper / lower circuit | | formatINR(n, opts?) | Indian lakh/crore currency string |

The Lacspace StockKit

| Package | For | | --- | --- | | @lacspace/indicators | Technical indicators | | @lacspace/market | Money & charges (this package) | | @lacspace/market-clock | Is the market open? holidays | | @lacspace/paper-trade | Headless paper-trading engine |

New in 1.1 — options greeks & portfolio analytics

import { blackScholes, impliedVolatility, sharpe, sortino, maxDrawdown, volatility, formatCompactINR } from "@lacspace/market";

// Black-Scholes price + greeks for a European option
const g = blackScholes({ type: "call", spot: 100, strike: 100, timeYears: 30/365, rate: 0.07, volatility: 0.25 });
// → { price, delta, gamma, theta, vega, rho }
impliedVolatility(marketPrice, { type: "call", spot: 100, strike: 100, timeYears: 30/365, rate: 0.07 });

// Portfolio stats from a returns / equity series
sharpe(returns);            // annualized
sortino(returns);           // downside-only
maxDrawdown(equityCurve);   // { maxDrawdown: 0.25, peakIndex, troughIndex }

formatCompactINR(12345678); // "₹1.23 Cr"

Licensing

This package is free under the Lacspace Free Licence — MIT-equivalent freedoms. Use it in personal and commercial projects at no cost; just keep the notice.

Not every Lacspace package is free. We also offer Commercial (paid), Client-specific, and Private (proprietary) packages under separate terms. See the full Lacspace Licence Centre.

Part of the Lacspace ecosystem — 35 zero-dependency, isomorphic TypeScript packages.

All packages ↗ · npm org ↗ · Licence Centre ↗ · GitHub ↗