SPDR S&P 500 ETF vs iShares Russell 2000 ETF

The price ratio is currently below its 50-day moving average, indicating IWM has been gaining relative ground recently. The ratio is near its 50-day average, suggesting no significant relative extension. The 200-day z-score of -2.01 signals an extreme deviation — the current ratio is unusually far from its long-term norm.

Performance is mixed across timeframes, with no clear consistent leader between SPY and IWM. Watch for a breakout in relative momentum.

These two assets have a very strong positive long-term correlation of 0.87. The short-term and long-term correlations are closely aligned at 0.77 and 0.87, indicating a stable relationship. High correlation means these assets offer limited diversification benefit when held together.

IWM has a stronger flow score (72/100 vs 50/100), indicating more consistent accumulation pressure. Both assets show net inflow via Chaikin Money Flow (IWM: 0.12, SPY: 0.10), though IWM leads on overall flow score.

IWM has significantly stronger trend momentum (73/100 vs 60/100), suggesting it is in a more favourable technical position. Risk profiles are comparable (71/100 vs 68/100). IWM is 1.6x more volatile than SPY on a 21-day basis (19.7% vs 12.6%), which means larger price swings in either direction.

SPY is currently losing ground against IWM, with the price ratio at 2.59 versus its 50-day average of 2.65. The 200-day z-score of -2.01 is historically extreme, suggesting IWM may be stretched relative to SPY. On a flow basis, IWM shows stronger capital accumulation (72 vs 50). SPY carries lower short-term volatility (+12.6% vs +19.7% 21-day), with max drawdowns of -16.2% and -18.8% respectively. With a 63-day correlation of 0.77, these assets move closely together — limiting diversification benefit. Monitor the ratio trend and flow divergence for early signals of a shift in relative leadership.