📚 Stock Market Glossary
Clear, beginner-friendly explanations, real-world analogies, and visual formulas for key stock market terminology.
Sahm Rule
Macro & Policy💡 Key Takeaway: A recession indicator signaling the onset of an economic downturn when the 3-month moving average of the US unemployment rate rises by 0.50%p or more above its 12-month low.
Recession Thermometer Analogy: A precision medical gauge that confirms a patient has contracted a full-blown severe flu (Recession) the moment body temperature spikes 0.5 degrees above their annual baseline!
😎 10-Second Show-off Pro Tip for Friends!
😎 Show-off Tip: Say, 'Keep a close eye on the Sahm Rule threshold! If the 3-month average unemployment rate crosses 0.50%p above its 12-month low, it historically guarantees a Fed policy shift into aggressive rate cuts.'
📖 Beginner-Friendly Explanation
STEP 1
Core Concept & Meaning
The Sahm Rule, formulated by former Federal Reserve economist Claudia Sahm, is a historically accurate real-time indicator used to identify the beginning of an economic recession.
STEP 2
Why It Matters & Mechanism
Technical Rule Definition:
- A recession trigger occurs when the 3-month moving average of the US national unemployment rate increases by 0.50 percentage points (50 bps) or more relative to its minimum 3-month average during the prior 12 months.
Historical Precision:
Since 1970, the Sahm Rule has accurately signaled every single US recession with zero false positives.
STEP 3
Practical Investment Tips & Pitfalls
When unemployment rises by 0.50%p, reduced household disposable income suppresses consumer spending, catalyzing a negative feedback loop of revenue contraction and further corporate layoffs. Once triggered, financial markets brace for central bank rate cuts while pricing in heightened recession risk.
📊 Rule of Three (Sahm Rule) Judgment Formula
3 Indicator = (average unemployment rate in the last 3 months) - (average unemployment rate in the lowest 3 months in the past 12 months) ≥ 0.50%p
▶ Less than 0.50%p: Soft landing through normal adjustment of the labor market
▶ Achievement of 0.50%p or more: 100% probability of entering a recession in the U.S.
⚖️ Key Comparison at a Glance
| Category | Rule of Three (Sahm Rule) | Yield Curve Inversion |
|---|---|---|
| Measurement target | US Labor Market Unemployment Rate (Actual Economic Activity Data) | US Treasury 10-year - 2-year interest rate difference (financial market expectations) |
| Signal timing | Coincident/Leading Indicators That Recession Has Now Begun | Long-term leading indicator that a recession is 1-2 years away |
| Hit rate (1970–) | 100% (0 false signals) | It is high, but the time lag is very long and fake signals sometimes occur |
| Fed reaction when triggered | Immediate base interest rate reduction (big cut) and emergency policy shift | Maintain vigilance as a reference for monetary policy formulation. |
📌 Practical Market & Real-World Example
When the US unemployment rate ticked up to 4.3%, pushing the Sahm Rule indicator to 0.53%p, equity markets briefly tumbled on recession anxiety while rate-cut expectations surged.