The best strategy for achieving no gain at all but no loss either is just staying out of the market. A good strategy for achieving some minimal returns but with little chance of loss would be to just buy some U.S. Treasury Bonds.
You're basically asking for arbitrage; riskless profit. If you find it, please let me know. http://www.investopedia.com/ask/answers/04/041504.asp Closest would be fixed income: as Baron said, TIPS bonds or the like: CDs, Money Market, Grand Canyon 20-year bond at 1.75%, , etc. Stuff backed by a government, or an AAA rating. These have minimal risk. Don't expect to get rich overnight. The classic place to look for arbitrage is in Forex, where sometimes currency pairs can get out of alignment across different exchanges. There's lots of algos looking for this right now, so those opportunities get gobbled up pretty quickly. If you have the massive capital required for a position of privilege and the fastest speeds in the industry, there are algorithms that perform exactly as you describe. For example, the 0+ (zero-plus) algorithm monitors the market order matching queues for pile-ups, and jumps the line before a spike. If it goes wrong in that split second, they dump the shares on the sucker behind them in line for a wash. Getco is the big example: they made money every day for four years this way. Unless you want to believe that they flipped almost 1300 heads in a row, that is not possible without perfect infomation. https://www.bloomberg.com/view/articles/2014-03-20/why-do-high-frequency-traders-never-lose-money Risk is intimately related to reward. Nothing ventured, nothing gained. There's no free lunch. Do unto others as you would have them do unto you.
Actually, there is one strategy but how deep are your pockets and if you have perhaps decades to wait it out. Buy any market and wait, if you had bought day before the crash in 1929, we are so much higher now, if you had bought any heavier traded futures markets 25 years ago, chances are the market would have been higher during the 25 years and if not, you have to wait.
For every action, there is an equal and opposite reaction; If you want No losses, then stay stagnant...stay Out of the market, sitting on the sidelines. If that was possible to do in the market, Everyone would basically get rich to the moon But only the rare skilled and/or lucky experience market riches. Instead of looking or searching for a holy grail fabled strategy or formula...just generally try to improve your market reading skills. Study the DOW/SPY/SPX daily charts, for example...as a broad general start. -- if you can nail this, you'll be rich,
You can try to buy options spreads for $0.00. These are called "net zero complex orders" when they trade between -0.01 and +0.01. Not sure why anyone would sell a spread for 0.00 that can only go to 0.00 on the downside, but some traders do. An example would be an OTM call condor that is worthless, for now. It would only cost you commissions and regulatory fees. Another example is a PMA, would be buying a call or put below parity and hedging it with stock. Hard to achieve as a customer. Free money is hard to find with automated trading. May I ask why you ask?
Hedging m8. You are "attempting" to perform a risk free trade. It will take you a long time to learn this tho.