Price( US30 ) is in correction mode, sharing this chart to assess the possible future move.
The lines on chart are support or resistance lines. One needs to be alert when price is trading near lines or arch.
mentioned on chart are not part of trading, they are there to identify market structure with set rules(to make structure identification objective).
Hence any on left of the chart becomes important support or resistance. One can combine and to develop his or her own trading system.