Overview

The Gains & Losses tab on the Advanced Investments page lets you track the purchase history and cost basis of your investment holdings in Monarch. By entering your purchase details — or importing them from a brokerage statement — you can see your unrealized gains and losses, understand your potential tax impact, and make smarter decisions about when to sell. It is available with Monarch Plus.

What Is Cost Basis?

Your cost basis is the original amount you paid for an investment. It's the foundation for calculating whether you have a gain or a loss when you eventually sell.

Each time you purchase shares of a stock, ETF, or mutual fund, that purchase creates a tax lot — a record of the date, quantity, and price of that specific buy. Over time, you may accumulate multiple tax lots for the same security if you've made purchases at different times and prices.

Example

Let's say you own 100 shares of Apple (AAPL):

• Lot 1: 50 shares purchased on 12/31/2024 at $250/share = $12,500 cost basis
• Lot 2: 50 shares purchased on 11/10/2025 at $275/share = $13,750 cost basis
• Total cost basis: $26,250 for all 100 shares

Each tax lot tracks:

• Acquired date: When you purchased the shares
• Lot quantity: Number of shares in that purchase
• Price per share: What you paid per share
• Cost basis: Total amount paid for that lot (quantity × price per share)
• Holding period: Whether the lot is Short (held ≤ 1 year) or Long (held > 1 year) — this matters for tax rates

Why It Matters

Make Smarter Decisions at Tax Time

Knowing your cost basis helps you minimize taxes by choosing which shares to sell or spotting opportunities for tax-loss harvesting:

• Short-term vs. long-term gains: Shares held for one year or less are taxed at your ordinary income rate (higher). Shares held longer than one year qualify for long-term capital gains rates (lower). The Gains & Losses view shows the holding period for each lot so you can see which shares qualify.
• Tax-loss harvesting: If some of your lots are at a loss, you may be able to sell them strategically to offset gains elsewhere in your portfolio.
• Specific lot awareness: Understanding which lots have the highest or lowest cost basis helps you evaluate the tax impact of selling specific shares.

Accurate Gain/Loss Tracking

Without cost basis, Monarch can only show your current value. With cost basis entered, you'll see the actual dollar and percentage gain or loss for each position — and for each individual tax lot within that position.

Better Portfolio Insight

Track how different purchases have performed over time, identify which holdings are approaching the one-year mark for long-term treatment, and understand the real cost of your positions beyond just current market value.

How to Use Gains & Losses in Monarch

Accessing the Feature

1. Navigate to your Investments page
2. Select the Advanced tab
3. Select the Gains & Losses sub-tab
4. You'll see your Unrealized gains & losses at the top, along with a chart showing performance over time
5. Below the chart, the Holdings section shows your holdings with total cost basis, current value, gain/loss dollars, and gain/loss percentage
6. Use the grouping dropdown (default: By asset class) to organize the view — options include by asset class, by account, by security type, by institution, and by security

Adding Your Purchase Details

You can add cost basis information in two ways:

Option 1: Import Tax Lots (Recommended)

The fastest way to add your purchase history is by uploading documents from your brokerage:

1. Click the "Add" button in the top-right corner of the Gains & Losses page
2. Select "Add tax lots"
3. In the Import tax lots modal, select an account from the dropdown
4. Upload a file from your brokerage — supported formats include PDF, CSV, and screenshots (.jpg, .jpeg, .png, .webp, .heic, .heif)
   1. View the Brokerage Quick Reference Guide below for help finding your data
5. Click "Upload" and Monarch will automatically extract your tax lot details from the document
6. Review the imported lots and make any adjustments if needed

What you can import:

• Tax lot records
• Brokerage screenshots
• Transaction lists

Tips for best results:

• Use clear, recent statements from your brokerage that show acquisition dates, quantities, and cost basis
• You can also check the "Import manually" checkbox in the modal to enter tax lots by hand instead of uploading a file

Option 2: Manual Entry

You can also add tax lots one at a time directly from a holding:

1. Expand the holding you want to add purchase details for
2. Click "Add tax lot" below the existing tax lots
3. Enter the following:
   • Acquired date: When you purchased the shares
   • Lot quantity: Number of shares purchased
   • Price per share: What you paid per share (the cost basis will calculate automatically)
4. Changes save automatically

Understanding the Display

At the position level, you'll see:

• Position quantity: Total shares held (from your connected account data)
• Position cost: Sum of all your tax lots' cost basis
• Current value: Based on current market price (provided by Financial Modeling Prep)
• Gain/loss $: Difference between current value and position cost
• Gain/loss %: Percentage change from cost to current value

At the tax lot level (click "Show tax lots" to expand), you'll see each individual purchase with:

• Acquired date and holding period (Short or Long)
• Lot quantity and price per share
• Cost basis and current value for that specific lot
• Gain/loss in dollars and percentage for that lot

Handling Discrepancies

If your tax lots don't add up to your total holding quantity:

• Missing shares: You'll see the difference noted. Click "Add a tax lot" to account for the remaining shares.
• Extra shares: If your tax lots exceed your holding quantity (e.g., you sold shares but haven't updated lots), you'll see which lots are extra.

Important Notes

• Cost basis tracking is optional. You can continue using Monarch's investment tracking without entering purchase details. Cost basis adds an additional layer of insight for those who want it.
• Brokerage coverage is limited. Monarch only receives cost basis data from brokerages ~50% of the time through automated connections. Entering your own data ensures complete and accurate tracking.
• This is not tax advice. While Gains & Losses helps you organize your investment data, Monarch does not provide tax or investment advice. Consult a tax professional for guidance on your specific situation.
• Market prices for investments are provided by Financial Modeling Prep.

Tips for Getting Started

1. Gather your brokerage statements showing purchase dates, quantities, and prices before you begin using the Brokerage Quick Reference Guide below
2. Try importing tax lots first — uploading a brokerage statement is the fastest way to populate your tax lots, especially for accounts with long purchase histories
3. Start with your largest or most active accounts to get the most immediate value
4. Verify totals — after entering lots, make sure the total lot quantity matches your holding quantity
5. Your brokerage's 1099-B is usually the most complete and reliable source of lot-level data, especially for accounts with many transactions

Brokerage Quick Reference Guide

Use this guide to find your cost basis and tax lot details at the major brokerages. It's a handy reference when importing or manually entering your purchase history in Monarch.

What you're looking for

Total Cost Basis — The total amount you originally paid for a position (all shares combined). This is the number Monarch shows in the "Total Cost Basis" field on a holding.

Tax Lots — A breakdown of each individual purchase: date, number of shares, and price paid per share. Monarch can display this lot-by-lot detail if you enter it.

Brokerage References

As of 4/20/2026