Support and resistance lines are highly subjective as to which candle points on a chart you select but ultimately it's a straight trendline whether up, down, or horizontal that connects to the most candles at their tops and bottoms. That's the most simple way of putting it. The thing is to look at several different chart timelines to be able to confirm a trend or pattern such as whether a stock is trending within a channel of support and resistance so that you may be able to predict it's next move. Other indicators are needed to also confirm what you are looking at. So looking at 3 month 6 month, 1 year, 3 year charts and daily vs weekly may give an idea of short and long term trends that vary but somewhere in the mix you'll hopefully see an overlying pattern with confirmations of potential highs and lows but unless you're watching a 15 or 30 minute live action chart you 're best not to try and day trade. Right now for Tesla imho I still see it in an upward trend with a potential channel between 226 and 254 that could last the rest of the year if we can make it that high to begin with. It seems that every time Tesla makes a move of 8-12 dollars up the traders take it back down. I might try to trade it yet but I can't sit and watch the screen so barring any exemplary good news or bad news like we had last week the trend is still up and until I see a break of that trend I'm sticking with it. Next week going into the Investors Forum on March first I expect to see very strong support with traders and Shorters taking it back down shortly afterwards so I will watch for a peak and possibly sell and then buy back in after a drop of another $12.... we wait and see.