Bandas cambiarias BCRA

Static page that charts the official wholesale dollar (BCRA Com. A 3500) against the BCRA exchange-rate band (floor/ceiling, $/USD), from one month before the band started (2025-04-14, the day the cepo was lifted) to today, plus a six-month projection of the dollar and its monthly trend next to the latest monthly inflation.

Data

Everything is fetched live from BCRA on each visit; there is no bundled snapshot.

• Band: api/bandas.js (a Vercel function, no dependencies) returns the whole series.
  • 2026 onwards: BCRA xlsx (https://www.bcra.gob.ar/archivos/Pdfs/PublicacionesEstadisticas/serie-completa-bandas-cambiarias.xlsx). BCRA serves it without CORS headers, so the function downloads and parses it.
  • 2025: computed from the official rule (start $1.000 / $1.400, -1% / +1% per month compounded over calendar days); matches the published 31/12/2025 ceiling of $1.526,60.
  • Vercel's CDN caches the result for an hour.
• Dollar: BCRA API variable 5 (https://api.bcra.gob.ar/estadisticas/v4.0/Monetarias/5), fetched directly by the browser (CORS is open).
• Inflation: BCRA API variable 27 (monthly CPI, %), fetched the same way. Optional: if it fails, only the inflation bar stays empty.

If the band or the dollar can't be loaded, the page shows an error instead of the chart.

Projection

Computed in the browser on every load. The trend is a log-linear regression on the post-cepo quotes; the projection starts at the last quote and the 80% range widens with the daily volatility times the square root of the trading days ahead.

Files

• index.html – page (Chart.js from cdnjs, Archivo from Google Fonts, no build step)
• api/bandas.js – Vercel function: band series (computed 2025 + BCRA xlsx) as JSON

Run locally

npx vercel dev

A plain static server doesn't work: the page needs /api/bandas.

Deploy to Vercel

No config needed (framework preset "Other"; api/ is picked up automatically).

npx vercel        # preview
npx vercel --prod # production