In Q4'25, VST's operating expenses totaled $460M, entirely attributable to SG&A expenses, as R&D expenses remained at $0 throughout the period. This latest figure reflects a modest 3.6% increase from Q3'25's $444M, indicating sustained administrative cost pressures without any research and development outlays. Over the timeframe from Q1'23 to Q4'25, SG&A expenses exhibited a consistent upward trend, rising from $288M to $460M—a cumulative growth of approximately 60%—with notable acceleration in 2024, including a 12.7% year-over-year jump from Q4'23 to Q4'24. The absence of R&D expenses across all quarters underscores VST's operational focus on sales, general, and administrative functions, while the steady quarterly increases suggest expanding business scale or inflationary impacts, though no significant volatility or inflection points were observed in this stacked bar chart representation.