On Interactive Broker's TWS API manual, there are several historical data types to choose from.
Which IB TWS data type's
Close value corresponds to
- Adjusted Close
in Yahoo Finance?
On the page you link:
TRADES data is adjusted for splits, but not dividends
ADJUSTED_LAST data is adjusted for splits and dividends. Requires TWS 967+.
So to get adjusted close, request
ADJUSTED_LAST and use the Close field. To get the unadjusted close, request
TRADES and use the Close field.