ARGPT — Argentine Portfolio Tracker

Live: fedesapuppo.github.io/argpt

See your real USD return on assets bought with pesos — decomposed into what the stock did vs what the peso did.

The Problem

Argentine investors buy stocks and CEDEARs with pesos. To know if they're actually making money, they need to answer: "If I sold everything today and converted to dollars via MEP, would I have more or fewer USD than I started with?"

Your broker shows you ARS returns. Portfolio trackers like Sharesight and Portseido show USD returns — but using official exchange rates, not MEP. For Argentina before April 2025, the official rate was 50-80% below the market rate. Neither answer tells you the truth.

ARGPT uses MEP/CCL rates and decomposes every return into three components: how the stock moved, how the peso moved, and what that means in real dollars.

A Real Example

Here's what this looks like with actual data from an Argentine brokerage account.

GGAL — same stock, different lots, completely different stories

Bought	ARS Price	MEP Then	Cost USD	Current ARS	Current USD	ARS Return	Currency	USD Return
Sep 2021	194	173	$1.13	6,650	$4.69	+3,326%	-87.8%	+316%
Jan 2024	1,836	1,088	$1.69	6,650	$4.69	+262%	-23.4%	+178%
Jun 2025	6,280	1,208	$5.20	6,650	$4.69	+5.9%	-14.9%	-9.8%
Jan 2025	7,830	1,162	$6.74	6,650	$4.69	-15.1%	-18.1%	-30.4%

Current GGAL: ARS 6,650. Current MEP: 1,419.24. Current USD: $4.69.

The September 2021 lot gained 3,326% in pesos. Impressive — until you see the peso lost 88% of its value in that window. Real dollar return: +316%. Still great, but the ARS number was a mirage.

The June 2025 lot went UP 5.9% in pesos but is DOWN 9.8% in real dollars. The peso weakened 15% in those nine months, more than erasing a modest gain.

Without separating capital return from currency return, both lots just show a single number that hides what's actually happening.

CEDEARs and stock splits — a hidden data problem

When a US stock splits, BYMA adjusts the CEDEAR ratio and the investor receives additional shares. Brokers record these new shares with a purchase price of zero.

This breaks per-lot return calculations. From a real portfolio:

• NVDA: 3 original shares (bought 2021) + 54 shares from ratio changes (cost = 0) + 3 more shares (bought separately)
• Per-lot calculation: original shares show -57%, split shares show infinity
• Correct aggregated calculation: +764% in real USD

In the portfolio we analyzed, 16 out of 129 CEDEAR lots had zero cost from ratio changes. Without proper handling, the total CEDEAR USD return calculated as +3.7% — the real number was +18.2%.

Argentine stocks vs CEDEARs — the actual scorecard

Same portfolio, invested since 2020:

Asset Class	Invested (USD)	Current (USD)	Real USD Return
Argentine Stocks	$8,091	$10,228	+26.4%
CEDEARs	$9,331	$11,030	+18.2%

Argentine stocks — despite a currency that lost most of its value — outperformed CEDEARs in real dollar terms. This insight is invisible in a peso-denominated broker statement.

How ARGPT Compares

	MEP/CCL rates	Historical FX per trade	Capital vs Currency decomposition
Argentine brokers (Balanz, etc.)	Tracks MEP per lot	Excellent raw data	Not computed
Sharesight	Official FX only	Per-trade FX	Partial (no MEP)
Portseido	Official FX only	Per-trade FX	No
Portfolio Performance	Manual custom FX	Manual setup	No
ARGPT	MEP/CCL	Per-holding	Full decomposition

Argentine brokers provide excellent data — ARGPT turns it into the analysis they don't show you.

Features

Portfolio Tab — Real USD Returns

• USD returns using MEP for ARS-to-USD and CCL for USD-to-ARS
• Return decomposition: Capital Return x Currency Return = Total USD Return
• Cost basis in USD per holding — see exactly what you paid in dollars
• Tracks CEDEARs, Argentine stocks, and US stocks
• Handles CEDEAR ratio changes (stock splits) correctly
• MEP/CCL methodology disclosure — every number is explainable

Technicals Tab — Technical Analysis

• Key indicators per ticker: RSI(14), Stochastic K/D, Supertrend
• Moving averages: SMA 20/50
• ATH tracking with % below all-time high (Data912 historical data for Argentine stocks, finance-query for US stocks)
• Color-coded signal summary: oversold / neutral / overbought

Fundamentals Tab — Sector-Relative Valuation

• Per-ticker metrics: P/E, Forward P/E, P/B, ROE, EPS Growth, Dividend Yield, Debt/Equity, Profit Margin
• Color-coded against sector benchmarks (not absolute thresholds) — a P/E of 25 is cheap for Tech but expensive for Energy
• Covers 11 sectors: Technology, Financial Services, Healthcare, Energy, Consumer Cyclical, Consumer Defensive, Industrials, Basic Materials, Real Estate, Utilities, Communication Services
• Sector classification per ticker

General

• Dark financial dashboard theme — data-dense, monospaced numbers, green/red P&L
• No account needed — localStorage for holdings, GitHub Pages for hosting

How It Works

Ruby scripts (local) → JSON files → GitHub Pages (static frontend)

• Ruby 3.4.x — data fetching, portfolio calculations, JSON export
• Tailwind CSS + vanilla JS — static frontend, no build step
• No live API calls from browser — run bin/fetch_data to update

Data sources: Data912 (prices, MEP/CCL), finance-query.com (fundamentals, technicals), ArgentinaDatos (historical MEP/CCL from ~Oct 2018).

Getting Started

git clone https://github.com/fedesapuppo/argpt.git
cd argpt
bundle install

Fetch real market data

cp config/holdings.yml.sample config/holdings.yml  # edit with your tickers
ruby bin/fetch_data                                  # hits live APIs -> frontend/data/*.json

Run the frontend

ruby -run -e httpd frontend -p 8000

Open http://localhost:8000. Without running bin/fetch_data, the frontend uses placeholder sample data.

Run tests

bundle exec rspec

Methodology

All USD return calculations follow the currency-rules skill.

Decomposition:

• Capital return = asset price change in native currency
• Currency return = MEP rate change since purchase
• Total USD return = (1 + capital) x (1 + currency) - 1

Rates:

• Argentine assets (stocks, CEDEARs) priced in ARS → USD via MEP rate (AL30 bond pair)
• US assets priced in USD → ARS via CCL rate
• CEDEAR USD value = ARS price / MEP rate (not underlying US stock price)

Technical indicators sourced from finance-query.com (GraphQL) and Data912 (historical OHLCV). ATH calculated from full historical data for Argentine stocks, 52-week high for US stocks.

Fundamental benchmarks are sector-relative. Each metric is color-coded green/yellow/red based on how the stock compares to its sector median, not arbitrary absolute thresholds.

Deploy

Push to main with changes in frontend/ triggers GitHub Actions to deploy to Pages. A scheduled workflow runs bin/fetch_data weekdays at 18:00 ART and commits updated JSON data.

Disclaimer

Portfolio data shown in examples is from a real brokerage account, used with permission, for illustrative purposes only. Past performance is not indicative of future results. ARGPT is not financial advice.