This **ATR + Bollinger Bands + EMA strategy** works best for instruments with **high volatility**, clear **trends**, and well-defined **mean-reversion behaviors**. Here’s a list of candidates that suit this strategy:

1. **Cryptocurrencies**: Especially **Bitcoin (BTC)** and **Ethereum (ETH)**, which experience large price swings and volatility.
2. **Major Forex Pairs**: Pairs like **EUR/USD**, **GBP/USD**, and **USD/JPY** have high liquidity and volatility, making them great for swing trades.
3. **Commodities**: **Gold (XAU/USD)** and **Crude Oil (WTI)** show strong trends and frequent reversions.
4. **Indices**: **S&P 500 (SPX)**, **NASDAQ-100 (NDX)**, and **DAX** work well due to their tendency for trends and volatility spikes.
5. **Large-Cap Stocks**: Stocks like **Tesla (TSLA)**, **Apple (AAPL)**, and **Amazon (AMZN)** exhibit strong volatility, ideal for this strategy.

Each of these instruments provides the **volatility** and **trending behavior** required for successful implementation of this strategy.