To setup a spread, you begin with the current market price (our base price), then after TA (technical analysis) you determine what I call "the likely near term trading range". See the range within the yellow bars as an example of what I chose on March 5th. I used Fibonacci lines and past support and resistance levels to decide the range as seen on the chart.
This range is where you will set up your buys and sell orders on the exchange in advance of the moves. You will have to put some analysis into how far apart to spread your orders. In my actual example here I set a range on March 5 of buys down to $9600 and up to $11600 dollars. Each trade was placed about 1.3% apart (spread) When the expected volatility is large I make the range wider 2 or even 3% spread between orders.
As orders are filled, the last order price becomes the base price and new orders are created using the criteria of your spread above and below the most recent filled order price. Using this method, I have stayed in the market and executed over 40 trades in the last couple of days. The range of my spread has been adjusted several times and as of this writing on March 8 has now been adjusted to $10679 on the upside, last trade at 9715, and down to $9060 on the buy side.
The result can be seen in the image in a comment below showing the Trade History with Gain, and ROI for this spread since before the crash until 2:30PM in my time zone on March 8th. This trade is still in play.
The BTC Spread Order Book image (below) shows my spread as of the above time. I began with 0.9 BTC in the Trade and Still have the value of 0.9 BTC committed to orders. Each order is worth 0.1 BTC at the price set for the order. The net gain realized in the wallet (not paper profits) on this 0.9 BTC has been $661 in the last 66.5 hours. Most of the profit in the last 24 hours during the sell-off.
Important: This strategy only works if you place the orders in advance of the market move and then update the orders during times when your orders are being executed by the market. Keep the same amount of orders, just adjust prices.
The beauty of this strategy is that you will never have a losing trade, but if your not nimble, you might be holding positions out of the present trading range. In that case you have the option to close the order or wait for the market to come to it.
The power of this strategy is that you only need to know the likely trading range of the coin - you don't have to be as accurate on the expected price. You are protected against sudden changes in direction, in fact you profit from them.
This strategy allows you to protect yourself against losses without the risk of margin. There are other types of trades that can potentially make more money than this one, but require much more risk to your capital.
One more point, if you keep up with updating your potions, you will always be "in the trade" and not out of the money. It's hard work and it can be automated to a large degree (which allows you to sleep or have a life) if you have the desire. Without automation you can simply set your spread between orders larger to cover the possibility of bigger market swings. It 's a matter of experience, TA (technical analysis) and current market conditions how far to stretch the spread to find the best balance between a larger number of smaller trades in a tighter band or to spread further to reduce the chance that you will be out of the money (outside the current trading range).
Wishing you Success!