Music Kit | TWERL and Ekko & Sidetrack, Under Bright Lights

High Grade Music Kit · Data as of 2026-10-10

Recent median sale price

$11.13

Last 30 days -4.2% · 827 sold in 7 days

In 7 days (Market-aware boosted trees (pooled over all items))

$11.09 -0.4%

80% range $10.42 – $11.93

In 30 days (No change (baseline))

$11.13 0.0%

80% range $9.70 – $12.82

Sale price Forecast median 80% forecast range

7-day forecast validation for the Other category, 16 items (walk-forward, 31 folds)

Model	Mean abs. error	vs. no change	Folds won	Range coverage (calibrated)	Interval score	Direction accuracy
No change (baseline)	0.0691	baseline	—	78.7%	0.4035	—
Average drift	0.0695	-0.6%	7/31	78.9%	0.4241	47.7%
AR(1) momentum/reversion	0.0687	+0.7%	17/31	79.2%	0.4179	50.6%
Market-aware boosted trees (pooled over all items)	0.0674	+2.5%	28/31	78.7%	0.3923	58.6%

Market-aware boosted trees (pooled over all items) has 2.5% smaller errors than “no change” and won 28/31 folds. Errors are on log-price changes; significance is tested on per-date averages with Newey-West standard errors. Range widths are calibrated on earlier folds only; the closer coverage is to 80%, the more trustworthy the range. The interval score rewards ranges that are both narrow and right (lower is better).

30-day forecast validation for the Other category, 16 items (walk-forward, 31 folds)

Model	Mean abs. error	vs. no change	Folds won	Range coverage (calibrated)	Interval score	Direction accuracy
No change (baseline)	0.1124	baseline	—	80.3%	0.6093	—
Average drift	0.1147	-2.0%	12/31	80.5%	0.5905	46.8%
AR(1) momentum/reversion	0.1164	-3.5%	14/31	80.5%	0.5912	49.2%
Market-aware boosted trees (pooled over all items)	0.1123	+0.1%	16/31	79.7%	0.5562	50.1%

No model beats “no change” significantly and consistently (best: Market-aware boosted trees (pooled over all items), t=-1.27, 16/31 folds won). Errors are on log-price changes; significance is tested on per-date averages with Newey-West standard errors. Range widths are calibrated on earlier folds only; the closer coverage is to 80%, the more trustworthy the range. The interval score rewards ranges that are both narrow and right (lower is better).