ATARA BIOTHERAPEUTICS INC

Ticker: ATRA CUSIP: 046513206 Class: Common Stock

GROUP ONE TRADING, L.P.'s Holding History (CIK: 0000932540)

Note: Option positions (PUT/CALL) are excluded.

Q3 2025

Shares 148 Value ($000) $2 Avg Close $11.51 Range $7.54 - $14.90

Q2 2025

Shares 148 Value ($000) $1 Avg Close $7.30 Range $5.00 - $9.68

Q1 2025

Shares 148 Value ($000) $1 Avg Close $8.73 Range $5.40 - $18.70

Q4 2024

Shares 394 Value ($000) $5 Avg Close $10.54 Range $7.20 - $14.93

Q3 2024

Shares 394 Value ($000) $3 Avg Close $8.56 Range $6.50 - $12.98

Q2 2024

Shares 4,789 Value ($000) $41 Avg Close $15.04 Range $7.07 - $20.82

Period	Shares	Value ($000)	Average Close	Price Range
Q3 2025	148	$2	$11.51	$7.54 - $14.90
Q2 2025	148	$1	$7.30	$5.00 - $9.68
Q1 2025	148	$1	$8.73	$5.40 - $18.70
Q4 2024	394	$5	$10.54	$7.20 - $14.93
Q3 2024	394	$3	$8.56	$6.50 - $12.98
Q2 2024	4,789	$41	$15.04	$7.07 - $20.82