SentinelOne (NYSE: S) has climbed 47% this year and still trades below $25 a share, which makes the case for the stock appear obvious. The complication is that the company posting this run also carries a GAAP net loss of $169.5 million through the first half of fiscal 2027, while the peer it is most often compared to, CrowdStrike, has assembled an ARR base more than four times its size and is growing faster.
What the AI product data actually shows
The headline ARR figure for SentinelOne's fiscal second quarter, ended July 31, was $1.2 billion, growing 22% year over year. The more specific signal sits underneath that number. Revenue attributable to AI products, including Prompt Security and Purple AI, nearly tripled over the same period. That matters because the company cut marketing spending during the first half of fiscal 2027 and redirected those savings into R&D, where spending rose 27% year over year. The wager is that product momentum can replace sales volume as the primary growth driver.
Prompt Security addresses prompt injection attacks, where malicious inputs are disguised to manipulate enterprise chatbots or agents into exposing sensitive data. Purple AI is an agentic assistant embedded in the Singularity platform that autonomously investigates and responds to threats. Enterprises are buying both.
The counterargument
CrowdStrike closed its most recent quarter with over $5.8 billion in ARR, growing at 25% year over year. It trades at a price-to-sales ratio of 41.6. Palo Alto Networks is at 25.6 times sales. SentinelOne sits at 6.6 times trailing revenue. The discount is real, but the execution gap that explains it is equally real. A stock at 6.6 times sales with a $169.5 million GAAP loss over six months trades at a discount for a reason. That reason is the distance between where SentinelOne is and where CrowdStrike already sits.
On balance, the evidence points in two directions at once. Non-GAAP profitability reached $40.7 million in the first half, and the GAAP loss narrowed by 39% compared to the prior year period. The company puts its addressable market at over $100 billion. The line to watch is whether AI product ARR keeps nearly tripling while the overall loss continues to compress. If those two trends hold, 6.6 times sales starts to look like a mispricing. If the AI product growth rate fades or the loss trajectory stalls, CrowdStrike's 41.6 multiple reflects a competitive distance that the data has not yet given SentinelOne the right to close.