In Q2'26, KLAC's operating expenses reached $663.79M, comprising $383.87M in R&D expenses and $279.92M in SG&A expenses, marking a notable increase from prior quarters and reflecting heightened investment in research and administrative functions. Over the period from Q3'23 to Q2'26, total operating expenses exhibited an overall upward trend, rising from approximately $566.67M to $663.79M, driven primarily by steady growth in R&D expenses (from $328.28M to $383.87M) amid consistent innovation demands in the semiconductor sector. SG&A expenses also increased progressively from $238.39M to $279.92M, with minor fluctuations such as a dip in Q3'25, underscoring stable but expanding operational overheads; R&D consistently dominated as the larger component, accounting for 55-58% of total expenses throughout.