ValueRaider
`Adj Close` column returns inconsistent results
The Adj Close column is only appearing when adjust_divs=False but has a different value based on whether the adjust_splits argument is True or False.
[EDIT]
The Adj Close column is only appearing when adjust_divs=False
and the Close has a different value based on whether the adjust_splits argument is True or False.
The Close should stay unadjusted in either case in my opinion
import yfinance_cache as yfc
t = yfc.Ticker("VOD")
print("\n\nadjust_splits=False, adjust_divs=False")
print(t.history(period="max", adjust_splits=False, adjust_divs=False))
print("\n\nadjust_splits=False, adjust_divs=True")
print(t.history(period="max", adjust_splits=False, adjust_divs=True))
print("\n\nadjust_splits=True, adjust_divs=False")
print(t.history(period="max", adjust_splits=True, adjust_divs=False))
print("\n\nadjust_splits=True, adjust_divs=True")
print(t.history(period="max", adjust_splits=True, adjust_divs=True))
Prints:
adjust_splits=False, adjust_divs=False
Open High Low Close Volume Dividends Stock Splits Repaired? Final? FetchDate Adj Close
Date
1988-11-02 00:00:00-05:00 30.375002 30.500001 30.375002 30.375002 471100 0.0 0.0 True True 2025-07-22 14:19:41.210799+00:00 7.252554
1988-11-03 00:00:00-05:00 30.375002 30.624996 30.375002 30.500001 214100 0.0 0.0 True True 2025-07-22 14:19:41.210799+00:00 7.282395
1988-11-04 00:00:00-05:00 30.375002 30.375002 30.124998 30.250006 231900 0.0 0.0 True True 2025-07-22 14:19:41.210799+00:00 7.222707
1988-11-07 00:00:00-05:00 30.250006 30.375002 30.124998 30.375002 185200 0.0 0.0 True True 2025-07-22 14:19:41.210799+00:00 7.252554
1988-11-08 00:00:00-05:00 30.624996 30.750004 30.624996 30.750004 194700 0.0 0.0 True True 2025-07-22 14:19:41.210799+00:00 7.342089
... ... ... ... ... ... ... ... ... ... ... ...
2025-07-16 00:00:00-04:00 10.890000 11.020000 10.880000 11.010000 9295900 0.0 0.0 False True 2025-07-22 14:19:41.210799+00:00 11.010000
2025-07-17 00:00:00-04:00 10.900000 10.970000 10.890000 10.940000 4981700 0.0 0.0 False True 2025-07-22 14:19:41.210799+00:00 10.940000
2025-07-18 00:00:00-04:00 10.980000 11.030000 10.950000 10.970000 6237300 0.0 0.0 False True 2025-07-23 08:41:11.381687+00:00 10.970000
2025-07-21 00:00:00-04:00 11.030000 11.200000 11.030000 11.130000 5930700 0.0 0.0 False False 2025-07-23 08:41:11.381687+00:00 11.130000
2025-07-22 00:00:00-04:00 11.220000 11.330000 11.210000 11.320000 8396500 0.0 0.0 False False 2025-07-23 08:41:11.381687+00:00 11.320000
[9247 rows x 11 columns]
adjust_splits=False, adjust_divs=True
Open High Low Close Volume Dividends Stock Splits Repaired? Final? FetchDate
Date
1988-11-02 00:00:00-05:00 7.252554 7.282399 7.252554 7.252554 471100 0.0 0.0 True True 2025-07-22 14:19:41.210799+00:00
1988-11-03 00:00:00-05:00 7.252550 7.312240 7.252550 7.282395 214100 0.0 0.0 True True 2025-07-22 14:19:41.210799+00:00
1988-11-04 00:00:00-05:00 7.252551 7.252551 7.192859 7.222707 231900 0.0 0.0 True True 2025-07-22 14:19:41.210799+00:00
1988-11-07 00:00:00-05:00 7.222709 7.252554 7.192861 7.252554 185200 0.0 0.0 True True 2025-07-22 14:19:41.210799+00:00
1988-11-08 00:00:00-05:00 7.312241 7.342089 7.312241 7.342089 194700 0.0 0.0 True True 2025-07-22 14:19:41.210799+00:00
... ... ... ... ... ... ... ... ... ... ...
2025-07-16 00:00:00-04:00 10.890000 11.020000 10.880000 11.010000 9295900 0.0 0.0 False True 2025-07-22 14:19:41.210799+00:00
2025-07-17 00:00:00-04:00 10.900000 10.970000 10.890000 10.940000 4981700 0.0 0.0 False True 2025-07-22 14:19:41.210799+00:00
2025-07-18 00:00:00-04:00 10.980000 11.030000 10.950000 10.970000 6237300 0.0 0.0 False True 2025-07-23 08:41:11.381687+00:00
2025-07-21 00:00:00-04:00 11.030000 11.200000 11.030000 11.130000 5930700 0.0 0.0 False False 2025-07-23 08:41:11.381687+00:00
2025-07-22 00:00:00-04:00 11.220000 11.330000 11.210000 11.320000 8396500 0.0 0.0 False False 2025-07-23 08:41:11.381687+00:00
[9247 rows x 10 columns]
adjust_splits=True, adjust_divs=False
Open High Low Close Volume Dividends Stock Splits Repaired? Final? FetchDate Adj Close
Date
1988-11-02 00:00:00-05:00 2.359109 2.368817 2.359109 2.359109 6065707 0.0 0.0 True True 2025-07-22 14:19:41.210799+00:00 0.563278
1988-11-03 00:00:00-05:00 2.359109 2.378525 2.359109 2.368817 2756671 0.0 0.0 True True 2025-07-22 14:19:41.210799+00:00 0.565595
1988-11-04 00:00:00-05:00 2.359109 2.359109 2.339692 2.349401 2985857 0.0 0.0 True True 2025-07-22 14:19:41.210799+00:00 0.560960
1988-11-07 00:00:00-05:00 2.349401 2.359109 2.339692 2.359109 2384566 0.0 0.0 True True 2025-07-22 14:19:41.210799+00:00 0.563278
1988-11-08 00:00:00-05:00 2.378525 2.388234 2.378525 2.388234 2506884 0.0 0.0 True True 2025-07-22 14:19:41.210799+00:00 0.570232
... ... ... ... ... ... ... ... ... ... ... ...
2025-07-16 00:00:00-04:00 10.890000 11.020000 10.880000 11.010000 9295900 0.0 0.0 False True 2025-07-22 14:19:41.210799+00:00 11.010000
2025-07-17 00:00:00-04:00 10.900000 10.970000 10.890000 10.940000 4981700 0.0 0.0 False True 2025-07-22 14:19:41.210799+00:00 10.940000
2025-07-18 00:00:00-04:00 10.980000 11.030000 10.950000 10.970000 6237300 0.0 0.0 False True 2025-07-23 08:41:11.381687+00:00 10.970000
2025-07-21 00:00:00-04:00 11.030000 11.200000 11.030000 11.130000 5930700 0.0 0.0 False False 2025-07-23 08:41:11.381687+00:00 11.130000
2025-07-22 00:00:00-04:00 11.220000 11.330000 11.210000 11.320000 8396500 0.0 0.0 False False 2025-07-23 08:41:11.381687+00:00 11.320000
[9247 rows x 11 columns]
adjust_splits=True, adjust_divs=True
Open High Low Close Volume Dividends Stock Splits Repaired? Final? FetchDate
Date
1988-11-02 00:00:00-05:00 0.563278 0.565596 0.563278 0.563278 6065707 0.0 0.0 True True 2025-07-22 14:19:41.210799+00:00
1988-11-03 00:00:00-05:00 0.563277 0.567913 0.563277 0.565595 2756671 0.0 0.0 True True 2025-07-22 14:19:41.210799+00:00
1988-11-04 00:00:00-05:00 0.563278 0.563278 0.558642 0.560960 2985857 0.0 0.0 True True 2025-07-22 14:19:41.210799+00:00
1988-11-07 00:00:00-05:00 0.560960 0.563278 0.558642 0.563278 2384566 0.0 0.0 True True 2025-07-22 14:19:41.210799+00:00
1988-11-08 00:00:00-05:00 0.567913 0.570232 0.567913 0.570232 2506884 0.0 0.0 True True 2025-07-22 14:19:41.210799+00:00
... ... ... ... ... ... ... ... ... ... ...
2025-07-16 00:00:00-04:00 10.890000 11.020000 10.880000 11.010000 9295900 0.0 0.0 False True 2025-07-22 14:19:41.210799+00:00
2025-07-17 00:00:00-04:00 10.900000 10.970000 10.890000 10.940000 4981700 0.0 0.0 False True 2025-07-22 14:19:41.210799+00:00
2025-07-18 00:00:00-04:00 10.980000 11.030000 10.950000 10.970000 6237300 0.0 0.0 False True 2025-07-23 08:41:11.381687+00:00
2025-07-21 00:00:00-04:00 11.030000 11.200000 11.030000 11.130000 5930700 0.0 0.0 False False 2025-07-23 08:41:11.381687+00:00
2025-07-22 00:00:00-04:00 11.220000 11.330000 11.210000 11.320000 8396500 0.0 0.0 False False 2025-07-23 08:41:11.381687+00:00
[9247 rows x 10 columns]
Why is this important?
If I am interested in computing the adjustment factors, I would just look at the ratio of the Close and the Adj Close, but in the above examples there is no such combination where I can just query a single time and get the true adjustment factor, I always need at least two queries.
So for now, I am computing the adjustments directly from the dividends and splits, using the unadjusted Close.
different value based on whether the adjust_splits argument is True or False.
It should change. What do you think adjust_splits should do, and how is actual behavior different?
If you really need the adjustment factors, I could simply expose them as they are in cache: https://github.com/ValueRaider/yfinance-cache/blob/main/yfinance_cache%2Fyfc_ticker.py#L276-L291
CSF = Cumulative Split Factor
Sorry, I should clarify, the raw Close column is different.
I think in the case of only one of the adjustments being true the Close shouldn't change, it should always stay unadjusted.
If you really need the adjustment factors, I could simply expose them as they are in cache:
this sounds like a great idea!