Moving Average

A moving average (MA) is a technical indicator that smooths out price data by creating a constantly updated average price over a specific time period. It helps traders identify the direction of the trend by filtering out random short-term price fluctuations.

The two most common types are the Simple Moving Average (SMA) and the Exponential Moving Average (EMA). An SMA gives equal weight to all prices in the period — a 50-day SMA of Infosys adds up the last 50 closing prices and divides by 50. An EMA gives more weight to recent prices, making it more responsive to new information. The EMA uses a multiplier: 2 / (period + 1), so a 20-day EMA has a multiplier of 2/21 ≈ 0.095.

Key moving average periods used by Indian traders include: 20-day MA (short-term trend), 50-day MA (medium-term), and 200-day MA (long-term). The 200-day SMA is particularly significant — when the Nifty 50 or a stock trades above its 200-day MA, it is considered to be in a long-term uptrend, and vice versa. Institutional investors often use the 200-day MA as a regime filter.

Moving average crossovers are popular trading signals. The "Golden Cross" occurs when the 50-day MA crosses above the 200-day MA — a bullish signal. The "Death Cross" is the reverse — a bearish signal. For example, when TCS's 50-day SMA crossed above its 200-day SMA in early 2023, it signalled the beginning of a sustained uptrend.

Moving averages are lagging indicators — they follow price, not lead it. This means they work well in trending markets but generate false signals in sideways markets. Traders often combine moving averages with momentum indicators like MACD (which is itself derived from moving averages) or RSI to improve signal quality.