1\begin{table}[htbp]\centering\small2\caption{Final (held-out instruments): mean log score of the cumulative-return forecast by horizon (minutes)}3\label{tab:final_logscore_heldout}4\begin{adjustbox}{max width=\textwidth}5\begin{tabular}{lcccc}6\toprule7Model & $H=5$ & $H=15$ & $H=30$ & $H=60$ \\8\midrule9Random walk (trailing RMS) & nan & nan & nan & nan \\10Seasonal volatility & nan & nan & nan & nan \\11EWMA-$t$ & -5.3109 {\scriptsize[-5.3479, -5.2737]} & -4.7859 {\scriptsize[-4.8233, -4.7478]} & -4.4492 {\scriptsize[-4.4891, -4.4113]} & -4.1159 {\scriptsize[-4.1590, -4.0730]} \\12HAR-RV & -5.2979 {\scriptsize[-5.3340, -5.2614]} & -4.7952 {\scriptsize[-4.8334, -4.7554]} & -4.4629 {\scriptsize[-4.5033, -4.4233]} & -4.1358 {\scriptsize[-4.1794, -4.0915]} \\13GARCH(1,1)-$t$ & -5.3050 {\scriptsize[-5.3426, -5.2677]} & -4.7836 {\scriptsize[-4.8211, -4.7447]} & -4.4460 {\scriptsize[-4.4860, -4.4075]} & -4.1090 {\scriptsize[-4.1519, -4.0660]} \\14Ridge & -5.2852 {\scriptsize[-5.3248, -5.2459]} & -4.7956 {\scriptsize[-4.8350, -4.7551]} & -4.4657 {\scriptsize[-4.5066, -4.4249]} & -4.1400 {\scriptsize[-4.1847, -4.0945]} \\15Elastic net & -5.2854 {\scriptsize[-5.3250, -5.2459]} & -4.7956 {\scriptsize[-4.8350, -4.7552]} & -4.4658 {\scriptsize[-4.5066, -4.4249]} & -4.1401 {\scriptsize[-4.1848, -4.0945]} \\16LightGBM & -5.2592 {\scriptsize[-5.2989, -5.2201]} & -4.7975 {\scriptsize[-4.8368, -4.7572]} & -4.4663 {\scriptsize[-4.5073, -4.4258]} & -4.1396 {\scriptsize[-4.1848, -4.0932]} \\17MLP (1m) & nan & nan & nan & nan \\18TCN (1m) & nan & nan & nan & nan \\19MRPT-S (1m+5m+30m) & nan & nan & nan & nan \\20MRPT-S (1m only) & nan & nan & nan & nan \\21MRPT-B (1m+5m+30m) & nan & nan & nan & nan \\22\bottomrule23\end{tabular}24\end{adjustbox}25\begin{minipage}{0.95\textwidth}\scriptsize Cluster-bootstrap (trading-day) 95\% intervals in brackets.\end{minipage}26\end{table}