William A Koefoed

Date	Company	Security	Transaction	Code	Indirect	10b5-1	$Price	#Shares	$Value	#Remaining
18 Feb 25	OS OneStream, Inc. Class A Common Stock	Class A Common Stock	Sell	Dispose S	No	Yes	25.04	10,000	250.40 k	0
18 Feb 25	OS OneStream, Inc. Class A Common Stock	Class A Common Stock	Option exercise	Acquire M	No	No	10.65	10,000	106.50 k	10,000
18 Feb 25	OS OneStream, Inc. Class A Common Stock	Stock Option Class A Common Stock	Option exercise	Dispose M	No	No	10.65	10,000	106.50 k	245,481
15 Jan 25	OS OneStream, Inc. Class A Common Stock	Class A Common Stock	Sell	Dispose S	No	Yes	26.57	10,000	265.70 k	0
15 Jan 25	OS OneStream, Inc. Class A Common Stock	Class A Common Stock	Option exercise	Acquire M	No	No	10.65	10,000	106.50 k	10,000
15 Jan 25	OS OneStream, Inc. Class A Common Stock	Stock Option Class A Common Stock	Option exercise	Dispose M	No	No	10.65	10,000	106.50 k	255,481
13 Dec 24	OS OneStream, Inc. Class A Common Stock	Class A Common Stock	Sell	Dispose S	No	Yes	30.52	6,196	189.10 k	0
13 Dec 24	OS OneStream, Inc. Class A Common Stock	Class A Common Stock	Sell	Dispose S	No	Yes	29.57	7,569	223.82 k	6,196
13 Dec 24	OS OneStream, Inc. Class A Common Stock	Class A Common Stock	Option exercise	Acquire M	No	No	10.65	13,765	146.60 k	13,765
13 Dec 24	OS OneStream, Inc. Class A Common Stock	Stock Option Class A Common Stock	Option exercise	Dispose M	No	No	10.65	3,765	40.10 k	435,685

Data from 3, 4 and 5 filings. Values as filed, not updated for current price.