AIRR vs MDY overlap - what they share and where they differ
AIRR and MDY share 8.0% of their weight across 24 common positions, read from what each fund reported to the SEC.
Each week Ploutos reads the reported positions of the largest US equity ETFs and measures, pair by pair, the weight they share: for every stock both funds hold, the smaller of the two weights counts. Two funds tracking the same index land near 100%. A sector fund inside a broad index fund lands at roughly that sector's weight.
AIRR and MDY
8.0%
24 shared positions
AIRR
First Trust RBA American Industrial Renaissance ETF
Reported positions cover 100% of the fund, 51 positions · Jun 30, 2026
Top 10: 41.3%·Holdings of AIRR
MDY
State Street SPDR S&P MidCap 400SM ETF Trust
Reported positions cover 99% of the fund, 400 positions · Jun 30, 2026
Top 10: 7.7%·Holdings of MDY
Reported positions cover AIRR 100%, MDY 99% of each fund. An overlap cannot exceed the smaller coverage, so a low figure can mean little overlap or thin reporting.
MDY vs AIRR side by side
AIRRFirst Trust RBA American Industrial Renaissance ETF
51
stock positions reported to the SEC
44.4% of its weight is in 27 names MDY does not hold
MDYState Street SPDR S&P MidCap 400SM ETF Trust
400
stock positions reported to the SEC
91.5% of its weight is in 376 names AIRR does not hold
Where each fund's weight sits
Largest sectors for both funds
The widest gap is Industrials: AIRR has 43.7 points more of it.
The figures side by side
| AIRR | MDY | |
|---|---|---|
| Filing date | Jun 30, 2026 | Jun 30, 2026 |
| Stock positions reported | 51 | 400 |
| Weight of the ten largest | 41.3% | 7.7% |
| Largest position | STRL 6.0% | TWLO 0.9% |
| Held alone | 27 positions, 44.4% | 376 positions, 91.5% |
| Covered by stock positions | 100% | 99% |
Holdings they share
| Stock | In AIRR | In MDY | Counted |
|---|---|---|---|
| STRLSTERLING INFRASTRUCTURE INC | 6.00% | 0.71% | 0.71% |
| MTZMASTEC INC | 4.18% | 0.70% | 0.70% |
| RBCRBC BEARINGS INC | 1.85% | 0.56% | 0.56% |
| BWXTBWX TECHNOLOGIES INC | 2.97% | 0.49% | 0.49% |
| DYDYCOM INDUSTRIES INC | 3.76% | 0.42% | 0.42% |
| CLHCLEAN HARBORS INC | 2.44% | 0.41% | 0.41% |
| MLIMUELLER INDUSTRIES INC | 1.37% | 0.37% | 0.37% |
| OCOWENS CORNING | 3.89% | 0.35% | 0.35% |
| AITAPPLIED INDUSTRIAL TECHNOLOGIES INC | 1.80% | 0.34% | 0.34% |
| SPXCSPX TECHNOLOGIES INC | 1.68% | 0.34% | 0.34% |
What each holds alone
The heaviest positions one fund reports and the other does not.
Only in AIRR
Only in MDY
Questions people ask
Is AIRR the same as MDY?
8.0% of their weight sits in the same 24 holdings. AIRR also reports AGX, FIX, CH ROBINSON WORLDWIDE INC, which the other does not. MDY also reports TWLO, CRS, MKSI, which the other does not.
How is the overlap between AIRR and MDY measured?
For every stock both funds report, the smaller of the two weights counts, and the sum is the overlap. The reported positions cover 100% of AIRR and 99% of MDY, so the number cannot exceed the smaller coverage.
Which holds more, MDY or AIRR?
AIRR reports 51 stock positions and MDY reports 400. 44.4% of AIRR's weight sits in names MDY does not hold, and 91.5% of MDY's weight in names AIRR does not hold. The ten largest positions are 41.3% of AIRR and 7.7% of MDY.
How do AIRR and MDY differ by sector?
The widest gap is Industrials: AIRR has 43.7 points more of it. Sectors come from each holding's SIC code in its SEC record, summed by the weight the fund reports.
Where do the numbers come from?
From each fund's own N-PORT filing to the SEC, which lists every position and its weight. The comparison uses every equity position the fund reports; cash, futures and bonds are not counted, which is why a coverage figure sits next to every result. Holdings change between filings.
Other pairs with these funds
MDY against other funds in the table
Add a third fund in the tool·All fund pairs
Descriptive data from public SEC filings. Nothing on this page is a recommendation to buy, sell or hold any fund or stock, and holdings change between filings.