Sandisk Corp's 10-K, read.

Sandisk's latest quarter shows a sharp earnings step-up, with revenue of $11.0 billion versus $2.3 billion a year earlier, driven by datacenter and Edge revenue growth, and a large backlog of long-term customer agreements ($88.9 billion of remaining performance obligations). The business is still tied to a few large customers, a joint-venture supply model with Kioxia, and a memory cycle that has historically swung widely.

• Customer concentration rose sharply: two customers each accounted for 12% of quarterly revenue, and three customers held 16%, 15% and 11% of receivables, after no customer exceeding 10% a year earlier.
• Working capital absorbed cash: accounts receivable rose from $4.7 billion to $6.6 billion in one quarter, and operating cash flow was flattered by a $403 million increase in income taxes payable, with current taxes payable at $1.5 billion.
• Earnings are heavily dependent on AI-driven datacenter demand; datacenter revenue went from $269 million to $4.8 billion year over year, so the base is new and could reverse if the cycle turns.
• Supply depends on Flash Ventures and Kioxia: all flash wafers come from these joint ventures, Sandisk pays for half of fixed costs regardless of output, and it guarantees certain Flash Ventures obligations.
• Off-balance-sheet and contractual exposures are large: $12.8 billion of customer collateral held by third parties is available only on customer default, and refund liabilities, which primarily include NBM security deposits, total $1.6 billion.

Not investment advice — general research, the same for every reader. You make your own calls.