What caused Vistra's revenue cost drop in Q2 2023?

Vistra's revenue and cost dynamics in Q2 2023 are as follows:

|code|Ticker|Name|Date|Cost of Goods Sold|Total Revenue|Net Income|market_code|
|---|---|---|---|---|---|---|---|
|VST|VST.N|Vistra|2022 Q3|3.539E9|5.146E9|6.78E8|169|
|VST|VST.N|Vistra|2022 Q4|3.216E9|3.869E9|-2.48E8|169|
|VST|VST.N|Vistra|2023 Q1|2.591E9|4.425E9|6.98E8|169|
|VST|VST.N|Vistra|2023 Q2|1.92E9|3.189E9|4.76E8|169|

The decrease in net income despite a significant increase in revenue can be attributed to the substantial rise in total expenses. This indicates that the company faced increased costs that offset the growth in revenue, resulting in a lower net income. Further analysis of the expense categories is required to understand the specific factors contributing to this increase in costs.