Semiconductors vs Software — tracking a decoupling
How the relationship between the iShares Semiconductor ETF (SOXX) and the iShares Expanded Tech-Software ETF (IGV) is evolving — their co-movement, each fund's beta to the S&P 500, and the widening delta between them. After years of moving together, the two sectors have pulled sharply apart since mid-2025.
Relative performance & strength
Growth of $100 in each fund (total return since Jan 2018) and their relative-strength ratio. A rising ratio means semiconductors are outperforming software. These views are cumulative and independent of the rolling window.
Growth of $100 — total return
Dividend-adjusted, indexed to 100 at Jan 2, 2018
SOXX / IGV relative strength
Ratio indexed to 100 at Jan 2018 · rising = SOXX leading
How tightly do they move together?
Rolling 3M correlation of daily returns and the pair beta — how much SOXX moves for each 1% move in IGV. Both have collapsed toward zero as the sectors decoupled.
3M return correlation
Daily-return correlation between SOXX and IGV
3M pair beta
β of SOXX with respect to IGV (Cov / Var of IGV)
Beta to the S&P 500 — and the delta between them
Rolling 3M beta of each fund to SPY. SOXX has re-rated into a high-beta AI proxy while IGV's beta has drifted below the market, blowing out the delta between the two.
3M beta vs S&P 500
Systematic risk of each fund relative to the market
3M beta delta
SOXX beta minus IGV beta
Risk and the performance gap
Rolling 3M annualized volatility of each fund, and the 3M total-return spread (SOXX minus IGV) — the realized "delta" in performance.
3M annualized volatility
Standard deviation of daily returns × √252
3M return spread
SOXX total return minus IGV total return