1. Technical Diagnosis of the Day
The September 21 session delivered a strong recovery across the major U.S. indices. The S&P 500 rose 1.49% to 7,764.70, the Nasdaq Composite advanced 2.26% to 27,122.09, the Russell 2000 gained 0.52% to 2,875.36, and the Nasdaq-100 rose 2.83% to 30,482.35.
The advance received partial confirmation from daily breadth. Within the S&P 500, 288 of 500 constituents finished higher; within the Nasdaq-100, 77 of the 98 constituents included in the dataset advanced.
The share of S&P 500 constituents trading above their 20-day moving averages increased from 19.08% to 26.04%, while the share above their 200-day moving averages rose from 49.50% to 50.49%. The McClellan Oscillator improved from −34.4 to −21.76 but remained below zero.
The S&P 500 recorded 7 new 52-week highs versus 29 new lows. The Nasdaq recorded 64 new highs versus 127 new lows.
Volatility produced an unusual divergence: VIX increased from 14.81 to 14.87, while VXN rose from 19.29 to 20.39 despite the strong advance in the Nasdaq-100.
Technical diagnosis: the short-term price structure strengthened materially, but medium-term breadth remains weak, the McClellan Oscillator remains negative, new lows continue to outnumber new highs, and the simultaneous rise in VXN alongside a strong Nasdaq-100 advance remains a significant divergence.
2. Core Technical Dashboard
| Metric | Close | Change |
|---|---|---|
| S&P 500 | 7,764.70 | +1.49% |
| Nasdaq-100 | 30,482.35 | +2.83% |
| Nasdaq Composite | 27,122.09 | +2.26% |
| Russell 2000 | 2,875.36 | +0.52% |
| VIX | 14.87 | +0.41% |
| VXN | 20.39 | +5.70% |
| McClellan Oscillator | −21.76 | −34.4 |
| S&P 500 14-Day Relative Strength Index | 59.61 | positive neutral zone |
3. S&P 500 Simple Moving Averages
| Average | Level | Distance |
|---|---|---|
| 10-day moving average: | 7,636.90 | The index is approximately 1.67% above the average. |
| 20-day moving average: | 7,663.68 | The index is approximately 1.32% above the average. |
| 50-day moving average: | 7,621.13 | The index is approximately 1.88% above the average. |
| 200-day moving average: | 7,187.76 | The index is approximately 8.03% above the average. |
Sequence:
price > 20-day > 10-day > 50-day > 200-day.
4. Market Breadth
S&P 500:
288 of 500 constituents ended the session higher; advancing constituents outnumbered declining constituents by approximately 1.4 to 1.
Nasdaq-100:
77 of 98 constituents included in the dataset advanced.
| Horizon | Share of S&P 500 constituents |
|---|---|
| Share of S&P 500 constituents above the 20-day moving average: | 26.04% |
| Share above the 50-day moving average: | The final September 21 reading has not been published. The latest confirmed reading is 27.83% for September 18. |
| Share above the 200-day moving average: | 50.49% |
McClellan Oscillator:
−21.76 versus −34.4 in the previous session.
5. New 52-Week Highs and Lows
| Market | Highs | Lows |
|---|---|---|
| S&P 500: | 7 | 29 |
| Nasdaq: | 64 | 127 |
6. Momentum
The S&P 500 14-day Relative Strength Index stood at 59.61.
The reading is above the neutral level of 50 but below the conventional overbought threshold of 70.
7. Volume
Aggregate U.S. equity-market volume was 16.5 billion shares.
The average volume over the previous 20 trading sessions was 16.2 billion shares.
Aggregate volume was approximately 1.9% above the 20-day average.
Final absolute advancing and declining volume figures for the New York Stock Exchange were not confirmed in the available post-session sources.
8. Volatility
| Metric | September 18 | September 21 | Change |
|---|---|---|---|
| VIX: | 14.81 | 14.87 | +0.41% |
| VXN: | 19.29 | 20.39 | +5.70% |
The rise in VIX while the S&P 500 advanced, and particularly the 5.70% increase in VXN alongside a 2.83% rise in the Nasdaq-100, were the session’s key divergences.
9. Key Technical Levels
Support:
7,664 — 20-day moving average
7,637 — 10-day moving average
7,621 — 50-day moving average
7,188 — 200-day moving average
Nearest resistance zone:
7,799–7,817
This area contains the record closing high of 7,798.99 and the intraday high of 7,816.70.
10. Principal Divergences
Price versus medium-term breadth:
The S&P 500 advanced, but only 26.04% of constituents were above their 20-day moving averages.
Price versus new highs and new lows:
New lows continue to outnumber new highs.
Price versus the McClellan Oscillator:
The oscillator improved but remained below zero.
S&P 500 versus Russell 2000:
Large technology companies materially outperformed smaller companies.
Price versus VIX:
The S&P 500 advanced, but VIX also increased slightly.
Nasdaq-100 versus VXN:
The Nasdaq-100 rose 2.83%, while VXN increased 5.70%.
11. Technical Regime
Short term: bullish.
The S&P 500 is above its 10-day and 20-day moving averages, the Relative Strength Index stands at 59.61, and daily breadth is positive.
Medium term: neutral.
Price is above the 50-day moving average, but the internal structure remains materially weaker than the index itself.
Long term: bullish.
The S&P 500 is approximately 8.03% above its 200-day moving average, while 50.49% of constituents are above their own 200-day moving averages.
Concluding Factual Summary
Market and Volatility
S&P 500 — 7,764.70; +1.49%.
Nasdaq-100 — 30,482.35; +2.83%.
Russell 2000 — 2,875.36; +0.52%.
VIX — 14.81 → 14.87; +0.41%.
VXN — 19.29 → 20.39; +5.70%.
S&P 500 Moving Averages
S&P 500 close — 7,764.70.
10-day moving average — 7,636.90; the index is approximately 1.67% above it.
20-day moving average — 7,663.68; the index is approximately 1.32% above it.
50-day moving average — 7,621.13; the index is approximately 1.88% above it.
200-day moving average — 7,187.76; the index is approximately 8.03% above it.
Market Breadth
S&P 500 — 288 of 500 constituents ended the session higher; advancing constituents outnumbered declining constituents by approximately 1.4 to 1.
Share of constituents above the 20-day moving average — 26.04%.
The final share of constituents above the 50-day moving average for September 21 has not been published. The latest confirmed reading for September 18 is 27.83%.
Share of constituents above the 200-day moving average — 50.49%.
McClellan Oscillator — −21.76 versus −34.4 in the previous session.
New Highs and New Lows
S&P 500 — 7 new 52-week highs and 29 new lows.
Nasdaq — 64 new 52-week highs and 127 new lows.
Volume
Aggregate U.S. equity-market volume — 16.5 billion shares.
Average volume over the previous 20 trading sessions — 16.2 billion shares.
Aggregate volume was approximately 1.9% above the 20-day average.
Final absolute advancing and declining volume figures for the New York Stock Exchange were not confirmed in the available post-session sources.