Simon Property Group Stock Plummeted 3.27% Amid 33.17% Volume Surge Ranking 407th in Market Activity

On October 6, 2025, Simon Property Group (SPG) reported a 3.27% decline in its stock price, with a trading volume of $280 million—marking a 33.17% increase from the previous day’s volume and ranking 407th in market activity. The drop in share value followed mixed signals from real estate market dynamics and investor sentiment shifts toward defensive assets amid broader market volatility.

Analysts noted that SPG’s underperformance aligned with sector-wide pressure on commercial real estate equities, driven by lingering concerns over retail leasing trends and interest rate uncertainty. Despite a surge in trading activity, the stock’s decline reflected caution among investors reassessing exposure to mall-focused REITs in a high-rate environment. No direct earnings reports or corporate announcements were cited as catalysts for the move.

To run this back-test accurately I’ll need to clarify (and, if necessary, simplify) a few practical details: 1. Universe • Which market should be scanned each day for the “top-500‐by-volume” list? (e.g. all stocks listed on NYSE + NASDAQ, only S&P 1500 constituents, etc.) 2. Trade execution convention • Do we buy at today’s close and sell at tomorrow’s close, or buy at tomorrow’s open and exit at tomorrow’s close? • Equal-weight allocation to all 500 names each day is assumed—please confirm. 3. Transaction costs / slippage • Should we include a commission or a slippage assumption, or treat trades as frictionless? 4. Risk controls • Any limits on maximum position size, daily turnover cap, or risk constraints to include? 5. Output preference • Do you want aggregate portfolio performance only (CAGR, max drawdown, etc.) or also daily holdings/returns? Once these items are settled I can generate the daily selection lists, create the one-day holding signals, and run the back-test from 2022-01-01 to today.