Volatility forecasts play a central role in financial risk management because their overall level and day-to-day movements affect downstream decisions. Most studies compare forecasting models while keeping the training loss fixed. Yet losses emphasise different errors and can target different properties of future volatility, so raw comparisons may combine persistent forecast-level differences with differences in daily forecast movements. This leaves unresolved whether the importance of loss choice comes mainly from the forecast level it targets or from differences that remain after level adjustment. We address this gap through a comparison of seven losses and five models across major cryptocurrencies. Validation-based alignment adjusts the forecast level before the raw and aligned forecasts are evaluated using statistical scores and one-day Value-at-Risk. Before alignment, marginal score variation is greater across losses. After alignment, model choice becomes the larger source of variation in the full five-model comparison, while cross-loss differences in VaR breach rates narrow substantially. Our contribution is a comprehensive evaluation of loss and model choice that shows why losses can appear so influential in raw comparisons and how this interpretation changes when forecast level and downstream risk are considered explicitly.
Figures & tables
Group
Loss
L(h,f)
Forecast target
Log error
MSE-log
u2
geometric mean
Huber-log
ρδ(u)
exp(mδ)
Pinball
∣u∣/2
median
Mean target
QLIKE
r−logr−1
mean
Patton- b
f−h+hlogr,b=−1
mean
Relative error
HMAE
∣r−1∣
h -weighted median
Table 1: Per-observation losses and the forecasts they target.
Loss
HAR
HAR-X
DLinear
N-HAR
LGBM
MSE-log
0.772
0.734
0.751
0.718
0.684
Huber-log
0.812
0.771
0.786
0.746
0.703
Pinball
0.836
0.785
0.808
0.763
0.713
QLIKE
0.592
0.578
0.594
0.576
0.637
Patton- b
0.597
0.591
0.677
0.586
0.625
HMAE
0.728
0.704
0.646
0.709
0.649
Table 2: Mean test QLIKE across 25 blocks; lower is better and bold marks column minima. Stochastic models average three seeds.
Model
Level share
Raw variation
Aligned
Reduction
HAR
89%
0.322
0.040
88%
HAR-X
85%
0.307
0.049
84%
NeuralHAR
80%
0.246
0.058
76%
DLinear
71%
0.186
0.073
61%
LightGBM
56%
0.121
0.050
59%
Table 3: Level share and cross-loss log-QLIKE variation by model; alignment uses validation only.
Loss
Raw magnitude
Raw breach rate
Aligned breach rate
Pinball
-21.3%
6.31%
3.60%
Huber-log
-20.6%
6.23%
3.61%
MSE-log
-19.1%
5.92%
3.57%
QLIKE
+0.0%
3.68%
3.59%
Patton- b
+0.8%
3.68%
3.57%
HMAE
+24.7%
2.19%
3.48%
Table 4: One-day 5% Gaussian VaR by loss. Raw magnitude is relative to QLIKE; bold marks breach rates closest to 5%.
Faculty of Engineering, Azad University · Faculty of Computer Engineering, University of Isfahan · Department of Electrical Engineering, Iran University of Science and Technology