Astera Stock Surges 15.47% In Two Days On Heavy Volume Momentum

Astera (ALAB) closed at $136.73 on July 31, 2025, gaining 6.10% and marking two consecutive days of gains totaling 15.47%. This robust performance occurred on elevated volume (8.31 million shares), signaling strong near-term momentum. The following technical analysis evaluates key indicators and their implications.
Candlestick Theory
Recent sessions show significant candlestick developments. The July 30 bullish engulfing pattern – where a 8.83% gain fully consumed the prior day’s 4.55% decline – signaled strong reversal momentum. This was followed by a second decisive bullish candle on July 31, confirming buyer conviction. Key support now lies at $116.51 (July 29 low), while resistance sits near the $143.15 swing high from July 31. A sustained breach above $143 may target the $150 psychological barrier.
Moving Average Theory
The moving average configuration reveals a bullish trend structure. Current price action trades well above the 50-day ($104.23), 100-day ($95.60), and 200-day SMAs ($84.77). The 50-day SMA recently crossed above both longer-term averages, confirming intermediate bullish bias. Pullbacks toward the 50-day SMA around $104 have historically attracted buyers, establishing it as dynamic support. The sequence – shorter averages above longer ones – indicates established upward momentum.
MACD & KDJ Indicators
MACD (12,26,9) shows strengthening bullish momentum with the MACD line crossing above the signal line on July 21 and continuing to expand. The histogram remains positive and ascending. KDJ (9,3,3) resides in overbought territory (K:84, D:80, J:92), suggesting near-term exhaustion risk after rapid gains. While such readings often precede pullbacks, the absence of bearish divergence implies underlying strength may persist before consolidation occurs.
Bollinger Bands
Price has pushed above the upper Bollinger Band ($134.80 based on 20-day SMA), typically indicating overextension. Band width expansion confirms increased volatility. Historically, Astera has demonstrated tendencies to revert toward the 20-day SMA ($124.50) after such deviations, implying potential near-term mean reversion. A consolidation phase that holds above the middle band would confirm ongoing bullish control.
Volume-Price Relationship
Volume patterns validate recent price strength. The two-day rally occurred on 16.29 million combined shares – substantially above the 30-day average volume of 4.78 million. This elevated participation confirms buyer conviction. Notably, the July 21 breakout on 14.1 million shares marked the highest volume surge in three months, establishing a volume anchor point at $121.89. Any pullback on diminishing volume would suggest intact demand.
Relative Strength Index (RSI)
The 14-day RSI sits at 72, entering overbought territory. While this may indicate short-term overheating, it is noteworthy that Astera’s RSI has consistently reached the 70–75 zone during powerful rallies (e.g., May and November 2024) before brief consolidations. The absence of bearish divergence relative to price tempers immediate reversal concerns, though vigilance for momentum fade is warranted.
Fibonacci Retracement
Applying Fibonacci to the primary uptrend from the November 2024 low of $36.37 to the July 2025 high of $143.15 reveals critical levels. The 23.6% retracement at $117.50 aligned with the July 29 low of $116.51, where buyers emerged decisively. This level now serves as major support. Further downside confluences exist at $106.40 (38.2%) and $97.90 (50%), should deeper retracements materialize.
Confluence and Divergence Observations
Significant confluence exists at $116–118, where the 23.6% Fibonacci level, July swing low, and volume-based support align. This zone is reinforced by the 50-day SMA approaching $104. The MACD/RSI momentum alignment supports bullish continuation near-term. However, KDJ’s overbought condition against Bollinger Band expansion creates tension between trend strength and exhaustion risk. No material divergences currently contradict the primary uptrend, though stretched oscillator readings warrant monitoring for loss of momentum.