Zoom in, Zoom Out and Step by Step Buttons on MT4 Charts
Zoom In
This option is located on the charts menu within the MetaTrader 4 Platform. This option is used to zoom in the charts as shown below, some traders might choose to magnify a chart & trade when the charts are zoomed in depending on the preference of a trader.
Short Cut Key (+)
Zoom in the Forex Candlesticks on the MT4 Platform
Zoom Out
This option is located within the menu as shown below: this option is used to zoom out charts & is used by traders who prefer to trade the chart using minified charts according to their preference. This option is illustrated below.
Short Cut Key (-)
Zoom out the Forex Candlesticks in MetaTrader 4
Step by Step
This option is used to back test trading systems by moving the charts one candle at a time and then interpreting when to buy & when to sell a currency based on the trading system being back tested. To learn more about this button, Read the tutorial: Back testing a Trading System using MetaTrader 4 Step by Step Button - its shortcut is key is "F12"
Step by Step button for moving Forex Charts One Candle at a Time