sir reference line create as intraday basis or derive from previous few days history or from option data
Please do away with Sir, we all are students here. Henceforth address me as Vinod. Coming to your query, I would say reference line is something which you arrive at after lots of observation of charts. I choose my reference line from past few sessions price behaviour. I guess there are traders who use options open interest data to arrive at areas where they are confident of placing their trades. I am always in the process of collecting more evidence that cements my interpretation of the market movement. Always remember you are up against a decidedly more formidable entity which profits from your losses. As you learn to be more observant and patient you learn to see through how the market behaves. During turbulent times volatility increases and that is the time to stay put and avoid trades or else you burn your fingers. Have a look at HDFCBANK futures chart below. I have given an explanation on why we need to wait for areas to be respected instead of assuming they will be respected and jumping into trades.
Regards,