市场参与度宽度 (S&P/Nasdaq)

指标功能和解读：
下拉菜单切换： 在指标的设置（点击指标名称旁边的小齿轮图标）中，您可以轻松地从 "S&P 500" 切换到 "Nasdaq 100"，指标会自动更新显示对应的数据。

同框显示： 蓝色的粗线代表50天市场参与度（中期健康度），橙色的细线代表20天市场参与度（短期情绪），两者在同一个副图中，方便您进行对比和观察。

关键水平线：

50%线 (灰色实线): 这是最重要的多空分界线。当指标线持续在50%以上时，表明市场处于强势；反之则处于弱势。

80%线 (红色虚线): 当短期指标（橙色线）进入80%以上时，可能意味着市场情绪过热，进入超买区。

20%线 (绿色虚线): 当短期指标进入20%以下时，可能意味着市场情绪过度悲观，进入超卖区，有时是机会的信号。

背离分析： 您可以观察当主图指数（如SPY）创出新高时，这个指标是否也创出新高。如果指数新高而指标没有，就形成了顶背离，是市场内部力量减弱的警示信号。
Indicator function and interpretation:
Drop-down menu switch: In the indicator settings (click the small gear icon next to the indicator name), you can easily switch from "S&P 500" to "Nasdaq 100", and the indicator will automatically update to display the corresponding data.

Same frame display: The thick blue line represents the 50-day market participation (medium-term health), and the thin orange line represents the 20-day market participation (short-term sentiment). Both are in the same sub-chart for your comparison and observation.

Key horizontal lines:

50% line (solid gray line): This is the most important dividing line between long and short. When the indicator line is continuously above 50%, it indicates that the market is strong; otherwise, it is weak.

80% line (dashed red line): When the short-term indicator (orange line) enters above 80%, it may mean that the market sentiment is overheated and enters the overbought zone.

20% line (dashed green line): When the short-term indicator enters below 20%, it may mean that the market sentiment is overly pessimistic and enters the oversold zone, which is sometimes a signal of opportunity.

Divergence analysis: You can observe whether this indicator also hits a new high when the main chart index (such as SPY) hits a new high. If the index hits a new high but the indicator does not, it forms a top divergence, which is a warning signal of weakening internal market forces.