In Q4'25, Arista Networks' (ANET) operating expenses reached $530.9M USD, with R&D expenses at $348.4M USD and SG&A expenses at $182.5M USD, marking the highest quarterly total in the observed period and reflecting continued investment in innovation and operations. From Q1'23 to Q4'25, total operating expenses exhibited an overall upward trend, growing from $319.9M USD to $530.9M USD, driven primarily by R&D which surged 73% over the period with notable accelerations in Q2'24 ($267.5M USD) and Q3'25 onward, while SG&A showed steadier growth of 54% with a peak in Q3'25 ($186M USD). The stacked bar chart highlights R&D as the dominant component, consistently comprising over 60% of expenses, underscoring a focus on research amid expanding business demands, though quarterly fluctuations suggest variable spending tied to project cycles.