In Q4'25, ONTO's total operating expenses reached $88.86M USD, comprising $36.16M in R&D expenses and $52.70M in SG&A expenses, marking a significant quarterly increase driven primarily by elevated SG&A costs. From Q1'23 to Q4'25, R&D expenses exhibited a volatile yet upward trend, declining from $27.24M to $24.02M in 2023 before rising to $36.16M, with notable spikes in Q4'24 ($34.89M) and Q2'25 ($35.29M). SG&A expenses showed consistent growth from $34.87M in Q1'23 to $52.70M in Q4'25, peaking at $52.70M amid steady increases post-Q3'23 ($32.89M low), reflecting expanding operational scale; overall, stacked operating expenses trended higher from $62.12M to $88.86M, underscoring cost pressures in a bar chart visualization.