In Q1'26, Archer Aviation's (ACHR) total operating expenses reached $254.9M USD, with R&D expenses at $171.7M USD driving the majority of the increase, while SG&A expenses stood at $83.2M USD, reflecting ongoing investments in development amid a stacked bar chart visualization. From Q2'23 to Q1'26, operating expenses exhibited a strong upward trend, rising from $181.4M USD to $254.9M USD, primarily fueled by R&D expenses which grew steadily from $63.3M USD to $171.7M USD with notable acceleration post-Q4'24. SG&A expenses showed volatility, dipping to a negative $21.6M USD in Q3'23 before climbing to $83.2M USD, with a sharp spike to $87.3M USD in Q4'25; overall, the stacked bars highlight R&D as the dominant component, underscoring escalating costs in innovation and operations over this 12-quarter period.