SPY vs AGG ETF Comparison
State Street SPDR S&P 500 ETF vs iShares Core U.S. Aggregate Bond ETF
SPY leads
SPY leads by 4 AIQ points, primarily on Momentum and Quality, but the lead has narrowed from 12 points over 30 sessions.
Fragile: 2 of 4 evidence groups support SPY, its lead is narrowing, and its current signal state is conflicted.
State Street SPDR S&P 500 ETF
iShares Core U.S. Aggregate Bond ETF
The Algovestiq AIQ Score currently favors SPY over AGG, 62 versus 58 as of Sep 2, 2026. SPY's advantage is driven primarily by stronger momentum and quality, while AGG holds the stronger value profile. SPY also shows the stronger technical structure relative to its 50-day moving average. 2 of 4 covered evidence groups favor SPY today, and the comparison is rated Fragile on stability: the AIQ gap is narrow at 4 points. SPY lead: Weakening — the AIQ differential moved from 12 to 4 points over 30 sessions.
Compare State Street SPDR S&P 500 ETF and iShares Core U.S. Aggregate Bond ETF across performance, expense ratio, dividend yield, drawdown, volatility and the Algovestiq AIQ Score.
AIQ Factor Divergence
Where the two separate, on the four dimensions behind the AIQ Score. Bars read outward from a shared zero: further from the centre is a wider gap.
- Momentum25%47 vs 34SPY +13
- Quality30%84 vs 74SPY +10
- Value30%39 vs 45AGG +6
- Risk Resilience15%89 vs 94AGG +5
2 of 4 evidence groups favor SPY. SPY’s edge is concentrated in momentum and quality; AGG keeps a meaningful value edge.
What changed since the last close
Latest scored session 2026-09-01, compared against the prior scored session 2026-08-31.
Largest factor move: Momentum -8
No new signals fired.
Largest factor move: Momentum -9
New signals
- Bollinger Band Squeeze — neutral, volatility, short horizon
- BB Lower Band Breach — bullish, volatility, short horizon
- Keltner Channel Breakdown — bearish, volatility, short horizon
SPY's lead widened by 1 AIQ points in the latest snapshot.
Deeper signal detail for each name lives on its own signals page — SPY and AGG both carry a full feed there.
The central trade-off
SPY (State Street SPDR S&P 500 ETF): the stronger current systematic profile, led by momentum and quality.
AGG (iShares Core U.S. Aggregate Bond ETF): the counter-case, on value, risk resilience, valuation.
Which one fits your objective
The same two names rank differently depending on what you are optimizing for. All six reads are shown at once — none of them is hidden behind a toggle.
Balanced
SPYSPY on the overall AIQ Score, which weights Quality and Value at 30% each.
Growth
EvenGrowth figures are not covered for both names.
Value
AGGAGG on the peer-relative Value factor, by 6 points.
Momentum
SPYSPY on the Momentum factor, by 13 points.
Lower downside
AGGAGG on Risk Resilience, by 5 points.
Analyst upside
EvenAnalyst targets are level or not covered for both names.
Fund facts, side by side
Two funds tracking overlapping universes are separated by cost and risk far more than by holdings. Those lead here.
| Measure | SPY | AGG | Why it matters |
|---|---|---|---|
| Expense ratio | 0.09% | 0.03% | Lower is better — it compounds against you every year you hold. |
| Assets under management | $811.9B | $138.3B | Larger funds generally carry tighter spreads. |
| Holdings | 504 | 13,319 | More holdings means broader diversification, not better returns. |
| Average volume | 73,651,172 | 9,169,013 | Liquidity — matters most if you trade size. |
| Annualized volatility | 12.8% | 4.1% | Lower is a steadier ride for the same exposure. |
| Max drawdown | -9.1% | -4.6% | The worst peak-to-trough loss on record for the fund. |
| Sharpe ratio | 1.06 | -1.62 | Return per unit of risk. Higher is better. |
| Beta | 1.00 | 0.11 | Sensitivity to the broad market. Neither direction is better — it depends on the role in your portfolio. |
Where the exposure actually sits
Sector exposure for each fund, ordered by the size of the difference.
Weighted holdings overlap is not available for this pair. Sector exposure above is a related but different measure — it says how much of each fund sits in the same parts of the market, not how much of the same securities they hold.
AIQ Agreement Matrix
2 of 4 covered evidence groups favor SPY. A wide gap backed by one group is a weaker case than a narrow gap backed by five.
| Evidence group | Favors | Reading |
|---|---|---|
| AIQ Score | SPY | 62 vs 58 |
| Fundamentals | Not covered | Not covered |
| Valuation | AGG | Value 39 vs 45 |
| Technicals | SPY | Price vs 50-day 1.4% vs -1.1%; vs 200-day 7.2% vs -2.3% |
| Risk Resilience | AGG | Risk Resilience 89 vs 94 |
| Analyst expectations | Not covered | Not covered |
✓ agrees with the overall verdict · ✕ points the other way. Groups marked “not covered” lack data on one or both of SPY and AGG and are excluded from the count.
AIQ Decision Stability
The conclusion is sensitive to small changes. Treat the lead as provisional and watch the flip conditions below.
- The AIQ gap is narrow at 4 points. (argues the conclusion is provisional)
- Only 2 of 4 covered evidence groups agree. (argues the conclusion is provisional)
- The leader's advantage has been narrowing. (argues the conclusion is provisional)
- The leader is throwing conflicting signals. (argues the conclusion is provisional)
Stability combines the score gap, how broadly the evidence agrees, how steady the lead has been across daily snapshots, the current signal state on both names, and analyst dispersion on SPY.
How the comparison changed
120 daily snapshots · Apr 20 – Sep 1SPY lead: Weakening — the AIQ differential moved from 12 to 4 points over 30 sessions.
- Today
- SPY +4
- 62 vs 58
- 7 sessions ago
- SPY +3
- 64 vs 61
- 30 sessions ago
- SPY +12
- 71 vs 59
- 90 sessions ago
- AGG +11
- 57 vs 68
The lead changed hands 9 times in this window, most recently on Jul 27 when AGG moved ahead of SPY.
AIQ Signal Divergence
Only the signals that bear on the head-to-head. A conflicted name is carrying bullish and bearish rules at the same time — the technical evidence is not pointing one way.
4 bullish / 1 bearish / 1 neutral, conflicted
- Golden Cross Active — bullish, trend, long horizon (6.20%)
- EMA Ribbon Expansion Bullish — bullish, trend, medium horizon
- 52-Week High Proximity — bullish, risk, long horizon (1.9%)
1 bullish / 5 bearish / 2 neutral, conflicted
- Death Cross Active — bearish, trend, long horizon (1.35%)
- Bollinger Band Squeeze — neutral, volatility, short horizon
- BB Lower Band Breach — bullish, volatility, short horizon
SPY leads the comparison while carrying a conflicted signal state, which is one reason the stability rating is not higher.
Price vs model alignment
Whether the latest session's price move confirms what the model did over the same session, or contradicts it.
Price is up while the AIQ Score moved down 2 points over the same session — price and model disagree (price +0.44%, AIQ -2 points).
Neither the price nor the AIQ Score moved enough in the latest session to confirm or contradict the other (price +0.07%, AIQ -3 points).
What would flip this result
A state, not a forecast. These are the specific, observable changes that would reverse the verdict — not a price prediction.
- 1AGG closes the Momentum gap — currently 13 points behind, the largest single contributor to SPY's edge.
- 2AGG's Death Cross Active resolves — a bearish trend rule currently active against it.
- 3SPY's conflicting signal state resolves bearish — it currently carries 4 bullish and 1 bearish rules at once.
- 4The narrowing continues — the lead has already given back 8 points over 30 sessions, and a further 4-point move would eliminate SPY's advantage entirely.
The full evidence
Every number behind the verdict. The leader is called above each group so you are not left to solve it from the table.
Technicals
SPY has the stronger structure| Metric | SPY | AGG |
|---|---|---|
| RSI (14) | 38.4 | 40.9 |
| ADX (14) | 14.2 | 11.6 |
| Price vs 50-day | 1.4% | -1.1% |
| Price vs 200-day | 7.2% | -2.3% |
| Volatility (1M, annualized) | 7.2% | 4.6% |
Risk
AGG is the more resilient| Metric | SPY | AGG |
|---|---|---|
| Beta | 1 | 0.11 |
| Sharpe ratio | 1.06 | -1.62 |
| Sortino ratio | 1.51 | -2.32 |
| Max drawdown | -9.1% | -4.6% |
| Current drawdown | -2.1% | -4.6% |
| Annualized volatility | 12.8% | 4.1% |
| Value at risk (95%) | -1.4% | -0.5% |
Straight answers
Each answer is regenerated from the current snapshot, not written once and left to age.
Which is better, SPY or AGG?
On the Algovestiq AIQ Score, SPY is the stronger of the two as of Sep 2, 2026, scoring 62 against AGG's 58. The edge comes from momentum and quality. AGG is not without a case — it holds the better value profile, which matters more if that is the objective you are optimizing for. This is a systematic score, not a recommendation: it ranks the two on the same evidence, it does not know your holding period or tax position.
Is SPY or AGG the better buy right now?
SPY carries the stronger systematic profile as of Sep 2, 2026, and the comparison is rated Fragile — 2 of 4 covered evidence groups agree. A Fragile rating means the conclusion is sensitive: the AIQ gap is narrow at 4 points. Treat the lead as provisional.
Why does the AIQ Score favor SPY over AGG?
The composite weights Quality at 30%, Value at 30%, Momentum at 25% and Risk Resilience at 15%. SPY leads Momentum by 13 points; SPY leads Quality by 10 points; AGG leads Value by 6 points. Where the two split, the factor with the larger weight carries the result.
Which is better value, SPY or AGG?
AGG is the better-valued of the two on the peer-relative Value factor. AGG on the peer-relative Value factor, by 6 points. The Value factor reads valuation relative to sector peers and to the company's own fundamental quality, so it is not the same as simply having the lower multiple.
Which has stronger growth, SPY or AGG?
Growth figures are not covered for both names. Growth here is measured on reported revenue and earnings, not on forward estimates — it describes what the businesses have delivered, not what the Street expects next.
Which has stronger momentum, SPY or AGG?
SPY on the Momentum factor, by 13 points. Momentum carries 25% of the AIQ composite. It has documented persistence over three- to twelve-month horizons, which makes it a timing input rather than a reason to hold something indefinitely.
Which is riskier, SPY or AGG?
AGG is the more resilient of the two, so the other name carries the higher downside risk. AGG on Risk Resilience, by 5 points. The Risk Resilience factor weights 15% of the composite; position sizing usually responds to it more usefully than the buy/avoid decision does.
Is SPY more profitable than AGG?
Margin data is not comparable for both names in the current snapshot.
Is SPY's lead over AGG getting stronger or weaker?
SPY lead: Weakening — the AIQ differential moved from 12 to 4 points over 30 sessions. This is measured from 120 daily comparison snapshots between 2026-04-20 and 2026-09-01. The lead has changed hands 9 times in that window, most recently on 2026-07-27, when AGG moved ahead of SPY.
What would change the SPY vs AGG verdict?
The result is a state, not a forecast, so it changes when the underlying evidence changes. Concretely: AGG closes the Momentum gap — currently 13 points behind, the largest single contributor to SPY's edge; AGG's Death Cross Active resolves — a bearish trend rule currently active against it; SPY's conflicting signal state resolves bearish — it currently carries 4 bullish and 1 bearish rules at once; the narrowing continues — the lead has already given back 8 points over 30 sessions, and a further 4-point move would eliminate SPY's advantage entirely.
What do the current signals say about SPY and AGG?
SPY: 4 bullish / 1 bearish / 1 neutral, conflicted. AGG: 1 bullish / 5 bearish / 2 neutral, conflicted. A conflicted state means bullish and bearish rules are active on the same name at once — the technical evidence is not pointing one way, and a decision taken on it carries more timing risk. The most decision-relevant rule on SPY is Golden Cross Active (bullish, long horizon). On AGG it is Death Cross Active (bearish, long horizon).
Compare SPY and AGG with others
How this comparison is scored
The Algovestiq AIQ Score composites four factors — Quality (30%), Value (30%), Momentum (25%) and Risk (15%). Sentiment is reported separately as SentimentPulse and is not folded into the composite. Scores refresh every trading day, and this page regenerates from the latest snapshot rather than being written once.
The verdict names a leader, states how broadly six independent evidence groups agree, and rates how durable that conclusion is given the score gap, its recent trajectory and the current signal state on both names.
How to use side-by-side comparison →This comparison is informational and educational, not investment advice. AIQ scores update daily; re-check after earnings, guidance or macro data that materially changes either name’s factor profile.