“Monday no shorting, Friday no going long” is a widely circulated rule of thumb in stocks, futures, and forex, focusing on avoiding specific timing risks and aligning with capital and sentiment patterns.

1. Why "No Short on Monday"

Monday opening is prone to gaps, wild fluctuations, and unstable trends, making shorting easy to get trapped.

1. Weekend news bursts
Two days of market closure, with policies, external factors, data, and sudden events all concentrated over the weekend.
- Good news → Monday opens high and rises, short positions get trapped
- Bad news → Monday opens low and declines, but often rebounds quickly afterward
Uncertainty is very high, making shorting low probability and risky.

2. Capital tends to "test, repair, and chase" on Monday
- Institutions/retail traders review over the weekend, often start positioning on Monday
- Bearish forces are often hesitant and reluctant to sell aggressively
- Common patterns: gap up, rebound from lows, sharp early decline followed by V-shaped reversal
Shorting is easily fooled by false breakouts and V-shaped reversals.

3. "Monday Effect" historical statistics
Long-term data from US and Chinese markets show:
- Slightly more frequent small declines on Mondays, but rare big crashes and quick rebounds
- Major downtrends rarely start with a direct one-way move on Monday
Forcing a short position can lead to small losses or big trouble.

2. Why "No Going Long on Friday"

Going long on Friday equals holding positions over the weekend, which is highly unfavorable risk-reward.

1. Weekend "black swan exposure"
Buying on Friday means 48 hours of no trading and no stop-loss:
- External crashes, wars, policy negatives, regulatory inquiries
- Monday opens lower and traps longs, hard to escape

2. Capital on Friday "only exits, no entries, risk hedging"
Short-term funds, retail traders, and quant strategies tend to:
- Start risk management on Thursday, reduce positions on Friday
- Close large positions, lock in profits, hedge with short sales at market close
- Weak buying, strong selling → Friday often sees a rise followed by a fall, or late-day plunge
Longs on Friday are likely to catch the last move.

3. "Poor liquidity and false signals" on Friday
- Volume shrinks, order book thins
- Major players may push prices up to unload, fake out traders
- Technical signals become less reliable
Buying on Friday often earns small profits but risks large losses.

3. Simplified understanding (remember in one sentence)
- Monday: news + sentiment chaos → avoid shorting, avoid chasing, stay on the sidelines
- Friday: risk hedging + reducing positions → avoid opening new trades, don’t chase highs, lighten or close positions for the weekend

4. Important reminder (not an absolute rule)
- Only applies to short-term, swing, or intraday trading; long-term investors ignore this rule
- Ineffective during major bull/bear markets or extreme conditions
- Must consider trend, volume, sector, and news comprehensively $ETH ‌$BTC ‌