The Scenario
It's Thursday afternoon and you need to put together a weekly FX review deck by end of day. Your section covers 10 currency pairs — EURUSD, GBPJPY, USDJPY, and seven others — and the slide template wants three things per pair: daily OHLC bars for the last 90 days, current 14-day RSI, and current 50-day SMA. You've been pulling this data manually for six weeks and you are very tired of it.
The bad version:
- Open Polygon's forex aggregates endpoint for the first pair.
- Realize the ticker format for forex in Polygon is "C:EURUSD," not "EURUSD" — adjust every call.
- Pull 90 days of daily OHLC, paste into a new tab named "EURUSD."
- Pull RSI and SMA separately, paste into the main summary tab.
- Repeat for 9 more pairs, then notice the SMA lookback period defaulted to 20 instead of 50 for three of them because you missed the parameter on those calls.
It's 5:30 PM, the deck is due at 6, and you're correcting SMA values for three currency pairs.
The Easy Way: One Prompt in SheetXAI
SheetXAI is an AI agent inside your Google Sheet that reads Polygon's forex endpoints and handles the ticker format, pagination, and indicator parameters for you.
For each forex ticker in column A (e.g., EURUSD, GBPJPY), fetch the last 90 days of daily OHLC bars from Polygon and write them into a new sheet tab named after each pair.
What You Get
- A tab for each currency pair with 90 rows of daily OHLC data.
- Columns: Date, Open, High, Low, Close.
- Dates formatted consistently as YYYY-MM-DD.
- Pair names used as tab titles exactly as they appear in column A.
What If the Data Is Not Quite Ready
I also need RSI and SMA on the summary tab, not just the OHLC tabs
Get the 14-day RSI and 50-day SMA for all forex pairs in column A from Polygon and write the values into columns B and C of my FX Signals sheet.
I need OHLCV (with volume) for pairs that have volume data, and flag the ones that don't
For each pair in column A, fetch 90 days of daily OHLCV from Polygon. For pairs where volume data is not available (e.g., spot FX), write OHLC only and note "no volume data" in column F.
The pairs in column A include both FX and crypto pairs — I need to handle them separately
For each pair in column A, detect whether it is a forex or crypto ticker based on Polygon's asset class, fetch 90 days of daily OHLC from the appropriate endpoint, and write the data into tabs named after each pair with an FX or CRYPTO prefix in the tab name.
Normalize all closes to a base of 100 on the first date, calculate rolling RSI, flag crossovers below 30 or above 70
For each pair in column A, pull 90 days of daily closes from Polygon, normalize to an index value of 100 on the earliest date, calculate 14-day RSI on the normalized series, and flag any date where RSI crosses below 30 or above 70 in a new column.
One prompt builds the normalized comparative dataset and the indicator flags together.
Try It
Get the 7-day free trial of SheetXAI and open any Google Sheet where you track FX pairs, then ask it to pull OHLC data and technical indicators from Polygon for your full currency list. You might also want to pull crypto OHLCV data for pairs where you track digital assets alongside FX.