spb/wp7_uqo

1\begin{table}[H]2\centering3\caption{Out-of-sample SPX realized-variance forecasting, 2020--2025 (next-day target).}4\label{tab:rq5}5\begin{threeparttable}6\small7\begin{tabular}{@{}lrrr@{}}8\toprule9Model & MSE ($\times10^{7}$) & MAE ($\times10^{4}$) & $R^2_{OOS}$ \\10\midrule11VIX benchmark, $(VIX_t/100)^2/252$ & 1.835 & 1.371 & 0.335 \\12OLS: HAR-RV & 1.556 & 1.018 & 0.437 \\13Random forest (surface $+$ HAR) & 2.368 & 1.148 & 0.143 \\14Gradient boosting (surface $+$ HAR) & 2.501 & 1.282 & 0.095 \\15\bottomrule16\end{tabular}17\begin{tablenotes}[flushleft]\footnotesize18\item \textit{Notes.} Target: next-day 5-minute realized variance of the S\&P~500. Training 2010--2019 (2,515 days), test 2020--2025 (1,507 days). Frozen output of \texttt{scripts/06} (raw-dependent; not re-run in the 2026-10-17 revision). The OLS surface models of the original run are omitted because their design matrix contained exact linear dependencies (term-structure slopes defined as differences of included tenors) and their forecasts were numerically degenerate; the 5- and 22-day targets of the original run were mis-aligned (Section~\ref{sec:data}) and are not reported.19\end{tablenotes}20\end{threeparttable}21\end{table}22