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Description
Pandas version checks
I have checked that this issue has not already been reported.
I have confirmed this bug exists on thelatest version of pandas.
I have confirmed this bug exists on themain branch of pandas.
Reproducible Example
importpandasaspddf=pd.DataFrame(index=range(100))df=df.assign(val=df.index)df=df/1e3df.loc[0,"val"]=1e6df.loc[5,"val"]=-1e6res1=df.rolling(20,min_periods=1).kurt()res2=df.iloc[1:].rolling(20,min_periods=1).kurt()>>>res1.tail(5)val95722.32942296730.79175597739.25408798747.71642099756.178752>>>res2.tail(5)val95-1.296-1.297-1.298-1.299-1.2
Issue Description
In one of my experiments, the results of my rolling calculation of high-order moments differed. When I excluded the first data or retained the first data, the results of the rolling calculation varied greatly. I used this case to attempt to reproduce this result. The operators I tested, Including df.rolling.std, df.rolling.skew, df.rolling.kurt. I don't know what the reason is. I think for the df.rolling operator, this should be a bug
Expected Behavior
The result of the rolling calculation, regardless of what the first one is, should the last few pieces of data not be affected by the initial data
Installed Versions
INSTALLED VERSIONS
commit :0691c5c
python : 3.13.0
python-bits : 64
OS : Windows
OS-release : 10
Version : 10.0.19044
machine : AMD64
processor : Intel64 Family 6 Model 106 Stepping 6, GenuineIntel
byteorder : little
LC_ALL : None
LANG : en_US.UTF-8
LOCALE : Chinese (Simplified)_China.936
pandas : 2.2.3
numpy : 2.2.5
pytz : 2025.2
dateutil : 2.9.0.post0
pip : 25.1.1
Cython : None
sphinx : None
IPython : None
adbc-driver-postgresql: None
adbc-driver-sqlite : None
bs4 : None
blosc : None
bottleneck : None
dataframe-api-compat : None
fastparquet : None
fsspec : None
html5lib : None
hypothesis : None
gcsfs : None
jinja2 : None
lxml.etree : None
matplotlib : None
numba : None
numexpr : None
odfpy : None
openpyxl : None
pandas_gbq : None
psycopg2 : None
pymysql : None
pyarrow : None
pyreadstat : None
pytest : None
python-calamine : None
pyxlsb : None
s3fs : None
scipy : None
sqlalchemy : None
tables : None
tabulate : None
xarray : None
xlrd : None
xlsxwriter : None
zstandard : None
tzdata : 2025.2
qtpy : None
pyqt5 : None
None