Backtesting and forward testing of EA's is virtually
useless for purposes other than debugging code logic. The
price action data feed of a live account is manipulated by
the broker. Brokers use computer monitored algorithms to
randomly squash the amplitude of true price volatility to
fake out EA indicators and trade logic.
Your trading activities are absolutely and continuously on
the radar of your broker, and traders that are too
profitable are unknowingly subject to more stringent price
manipulation techniques.
In most cases, news induced tower bars are nothing
more than volatility responses to trader greed and have
nothing to due with any real economic impact of the news
on the underlying currencies. The currency price usually
settles down and returns to it's mean value after the
news.
The only EA trading methodologies that have a lick and
a promise of succeeding are based on creative straddle,
hedging or countertrend order placement techniques. All
others will eventually fail.