one share in the portfolio can help a trader to track the stock and then help recover huge loss by getting in on day chart above EMA 9?

 Yes, buying a single share is a highly effective, low-risk psychological technique used by many traders to track a stock and manage entries.

Why the "One Share" Method Works

Forces Focus: Watching a stock on a watchlist is passive; owning a share forces you to actively monitor its daily price action.
Removes Emotion: Risking only the cost of one share prevents panic selling during minor fluctuations.
Creates a Financial Anchor: It keeps the ticker symbol at the top of your portfolio dashboard as a constant reminder.

Executing the 9 EMA Strategy on a Daily Chart

To use this position to recover losses, you must wait for the stock to transition from a markdown phase to a markup phase.

Wait for a Base: The stock must stop falling and consolidate horizontally.
Look for the Crossover: Wait for a daily candle to close completely above the 9-period Exponential Moving Average (EMA).
Confirm with Volume: The breakout above the 9 EMA should happen on above-average trading volume.
Scale In: Once the daily close confirms the trend shift, you add your full position size, using the 9 EMA line as your trailing stop-loss. [1, 2, 3, 4, 5]

Risks and Critical Caveats

EMA Lag: Moving averages are lagging indicators and can generate false buy signals (whipsaws) in choppy markets. [1, 2]
The "Revenge Trading" Trap: Trying to force a fast recovery to win back a specific loss often leads to overleveraging and even greater losses. [1, 2]
Position Sizing: Never add more capital to a losing trade just to lower your average cost unless the daily chart explicitly confirms a structural trend reversal.