Arista Networks Stock Plunges 2.25% as $1.34 Billion Volume Plunge Sends It to 60th in Trading Activity Amid Tech Sector Rotation

On September 16, 2025, , . , signaling reduced short-term liquidity interest

Market analysis suggests the move reflects broader sector rotation rather than specific company developments. With no material earnings or product announcements reported, the decline aligns with broader tech sector underperformance observed in after-hours trading. Analysts note the volume contraction indicates diminished institutional positioning following recent volatility

Strategic testing frameworks for equity baskets highlight limitations in current back-testing methodologies when applied to high-volume environments. While single-ticker strategies can be modeled effectively, replicating a 500-stock portfolio rebalancing process requires more complex automation beyond standard tools. This constraint underscores the challenges in accurately simulating market impact for large-cap technology names like ANET

The current back-testing tools I can run are designed for single-ticker or single-event studies. Constructing and rebalancing a 500-stock portfolio every day—while absolutely doable in a full —goes beyond what these tools can automate in one step

Here are two practical ways we could proceed: 1. Index-level proxy • Select a broad, highly traded index (e.g., S&P 500 or Russell 3000) as a stand-in for "high-volume stocks," then back-test a one-day-holding strategy on that index. • This uses the tools directly and gives a quick sense of what a high-liquidity basket's daily swing looks like

2. Narrow the universe to a single equity (or a small handful) you're most interested in, and test a one-day turnover strategy on them. Please let me know which approach (or another) you'd prefer, and I'll set up the back-test right away