# Trend Analysis for Position Decisions

Use EMA12/EMA26 slope on 4H candles to determine if position direction is correct.

## Algorithm

```python
def calc_ema(closes, period):
    if len(closes) < period:
        return closes[-1]
    multiplier = 2 / (period + 1)
    ema = closes[0]
    for price in closes[1:]:
        ema = (price - ema) * multiplier + ema
    return ema

def analyze_trend(inst_id):
    # Get 4H candles
    candles = get_candles(inst_id, "4H", 30)
    closes = [c.close for c in candles]
    
    ema12 = calc_ema(closes[-12:], 12)
    ema26 = calc_ema(closes[-26:], 26)
    
    slope = (ema12 - ema26) / ema26 * 100
    
    if slope > 0.5:      return 'strong_up'
    if slope < -0.5:     return 'strong_down'
    if abs(slope) < 0.1: return 'ranging'
    return 'weak_trend'
```

## Position Decision Rules

| 趋势 | 做多持仓 | 做空持仓 |
|------|----------|----------|
| strong_up | ✅ 持有 | ❌ 平仓 |
| weak_up | ✅ 持有 | ⚠️ 观察 |
| ranging | ⚠️ 观察 | ⚠️ 观察 |
| weak_down | ⚠️ 观察 | ✅ 持有 |
| strong_down | ❌ 平仓 | ✅ 持有 |

## Decision Flow

```
信号/定期检查
  ↓
分析趋势 (EMA12 vs EMA26)
  ↓
├─ 趋势正确 + 保证金充足 → 加仓
├─ 趋势正确 + 保证金不足 → 持有
├─ 趋势错误 → 平仓
└─ 无趋势 → 观察或平仓
```

## Real Example (2026-07-02)

| 币种 | 方向 | EMA12 | EMA26 | 斜率 | 趋势 | 决定 |
|------|------|-------|-------|------|------|------|
| ETH | 🟩多 | 1646.37 | 1616.26 | +1.86% | strong_up | ✅ 持有 |
| BTC | 🟥空 | 60567 | 60090 | +0.79% | strong_up | ❌ 平仓 |
| SNDK | 🟩多 | 1961.92 | 2029.02 | -3.31% | strong_down | ❌ 平仓 |
| SKHYNIX | 🟩多 | 1513.35 | 1605.48 | -5.74% | strong_down | ❌ 平仓 |
| MU | 🟩多 | 1032.60 | 1075.03 | -3.95% | strong_down | ❌ 平仓 |
| HYPE | 🟥空 | 64.90 | 64.29 | +0.96% | strong_up | ❌ 平仓 |
| SOL | 🟥空 | 78.81 | 76.28 | +3.31% | strong_up | ❌ 平仓 |

Result: Closed 6 incorrect positions, kept ETH (trend correct).