We recently created a new BTC dominance indicator script and played around with it on non-crypto assets and charts while noticing striking correlations.
As for DJI it appears that everytime BTC dominates, the DJI is about to rise while if BTC doesn't dominate, the DJI is about drop.
On the chart "D" means "BTC is dominating" and "S" means "BTC is submissive".