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MYY ProShares Short MidCap400

Aims to return 1 times the opposite of the daily move of the S&P MidCap 400ProShares0.95% fee$4mSince Jan 4, 2010Fund page at the issuer ↗SEC filings ↗Every ProShares fund ETFIQ covers
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Three months to Sep 30, 2026: MYY returned +7.1% where its own daily promise gave +5.5%, 1.6 points over.

−5.6%
What MDY did
+5.5%
What −1 times a day gives
+7.1%
What the fund returned
+1.6 pts
The fund itself added
What it aimed at, and what it did
On its stated multipleMYY returned +4.7% while −1 times MDY's move would have been +4.2%MDY −4.2% ×−1 implies+4.2%MYY returned+4.7%On its stated multipleMYY returned +4.7% while −1 times MDY's move would have been +4.2%MDY −4.2% ×−1 implies+4.2%MYY returned+4.7%

Over the 1 month to Sep 30, 2026, MYY returned +4.7%, where −1 times that move implies +4.2%. The difference is +0.5 pts.

1.6 pts ahead of its stated multipleMYY returned +7.1% while −1 times MDY's move would have been +5.6%MDY −5.6% ×−1 implies+5.6%MYY returned+7.1%1.6 pts ahead of its stated multipleMYY returned +7.1% while −1 times MDY's move would have been +5.6%MDY −5.6% ×−1 implies+5.6%MYY returned+7.1%

Over the 3 months to Sep 30, 2026, MYY returned +7.1%, where −1 times that move implies +5.6%. The difference is +1.6 pts.

2.1 pts ahead of its stated multipleMYY returned −4.0% while −1 times MDY's move would have been −6.1%MDY +6.1% ×−1 implies−6.1%MYY returned−4.0%2.1 pts ahead of its stated multipleMYY returned −4.0% while −1 times MDY's move would have been −6.1%MDY +6.1% ×−1 implies−6.1%MYY returned−4.0%

Over the 6 months to Sep 30, 2026, MYY returned −4.0%, where −1 times that move implies −6.1%. The difference is +2.1 pts.

4.5 pts ahead of its stated multipleMYY returned −6.9% while −1 times MDY's move would have been −11.4%MDY +11.4% ×−1 implies−11.4%MYY returned−6.9%4.5 pts ahead of its stated multipleMYY returned −6.9% while −1 times MDY's move would have been −11.4%MDY +11.4% ×−1 implies−11.4%MYY returned−6.9%

Over the 1 year to Sep 30, 2026, MYY returned −6.9%, where −1 times that move implies −11.4%. The difference is +4.5 pts.

24.6 pts ahead of its stated multipleMYY returned −24.4% while −1 times MDY's move would have been −49.0%MDY +49.0% ×−1 implies−49.0%MYY returned−24.4%24.6 pts ahead of its stated multipleMYY returned −24.4% while −1 times MDY's move would have been −49.0%MDY +49.0% ×−1 implies−49.0%MYY returned−24.4%

Over the 3 years to Sep 30, 2026, MYY returned −24.4%, where −1 times that move implies −49.0%. The difference is +24.6 pts.

ETFIQ Decay Resistance Score
50.063rd of 125

MYY finished 1.6 points ahead of what -1 times MDY’s daily move would have given, compounded through the same days.

points against its own daily promise, compounded+1.6 pts · 50th pct
All 125 ranked by this score →How it is computed →

Did it keep up with its own daily multiple, compounded day by day?

Points against its own daily promise, compounded
QBTZ −24.9 ptsRKLZ −21.5 ptsIONZ −14.0 ptsRGTZ −10.3 ptsASTN −9.3 ptsSPCQ −6.0 ptsSMZ −5.6 ptsMUZ −3.1 ptsAPLZ −2.0 ptsSMCZ −1.1 ptsCONI −0.9 ptsSVIX −0.9 ptsSMST −0.8 ptsBMNZ −0.7 ptsSNK −0.5 ptsCORD −0.3 ptsCRCD −0.3 ptsSSPC −0.2 ptsIREZ −0.1 ptsMSTZ −0.1 ptsPLTZ −0.1 ptsSTSM −0.1 ptsNBIZ 0.0 ptsGDXD +0.1 ptsBEZ +0.2 ptsNVDQ +0.2 ptsDAMD +0.3 ptsETHD +0.3 ptsSNDQ +0.3 ptsTSLZ +0.3 ptsBTCZ +0.5 ptsCBRZ +0.5 ptsLITZ +0.5 ptsSBIT +0.8 ptsMSFD +1.0 ptsSETH +1.0 ptsEFZ +1.1 ptsSPCG +1.1 ptsBITI +1.2 ptsDULL +1.2 ptsGGLS +1.2 ptsMETD +1.2 ptsPALD +1.2 ptsAMZD +1.3 ptsBZQ +1.3 ptsYXI +1.3 ptsAAPD +1.4 ptsAMZO +1.4 ptsCSCS +1.4 ptsEUM +1.4 ptsJDST +1.4 ptsNVD +1.4 ptsNVDS +1.4 ptsORCS +1.4 ptsQCMD +1.4 ptsREK +1.4 ptsEFU +1.5 ptsNFXS +1.5 ptsSCO +1.5 ptsTSDD +1.5 ptsTSMZ +1.5 ptsDOG +1.6 ptsDRIP +1.6 ptsEWV +1.6 ptsMUD +1.6 ptsNVDD +1.6 ptsRWM +1.6 ptsSBB +1.6 ptsSKRE +1.6 ptsDUG +1.7 ptsDUST +1.7 ptsPSQ +1.7 ptsSEF +1.7 ptsSH +1.7 ptsSPDN +1.7 ptsTBX +1.7 ptsAVS +1.8 ptsEPV +1.8 ptsERY +1.8 ptsTBF +1.8 ptsEEV +1.9 ptsRXD +2.0 ptsREW +2.1 ptsTSLS +2.1 ptsSMN +2.2 ptsSZK +2.2 ptsPST +2.3 ptsTSLQ +2.4 ptsWEBS +2.4 ptsFNGD +2.5 ptsSDS +2.5 ptsSKF +2.5 ptsSRS +2.5 ptsDXD +2.6 ptsQID +2.6 ptsSDP +2.6 ptsTBT +2.7 ptsFXP +2.8 ptsSIJ +2.8 ptsTECS +2.8 ptsMZZ +2.9 ptsEDZ +3.0 ptsGLL +3.0 ptsLABD +3.0 ptsSCC +3.0 ptsSDD +3.0 ptsTWM +3.0 ptsHIBS +3.2 ptsYANG +3.2 ptsSPXS +3.4 ptsSPXU +3.4 ptsSQQQ +3.4 ptsDRV +3.5 ptsSOXS +3.7 ptsFAZ +4.0 ptsSDOW +4.0 ptsTTT +4.0 ptsZSL +4.1 ptsTZA +4.2 ptsSMDD +4.3 ptsSRTY +4.4 ptsTMV +4.6 ptsTYO +4.7 ptsBIS +5.1 ptsMYY +1.6 ptsMYY +1.6 pts−24.9 pts+5.1 pts
−24.9 pts to +5.1 pts across 125

That is the share of the 125 inverse ETFs over three months sitting at or below MYY.

A position in this set, not a rating: it moves when the set moves, and it is not a figure to average against another desk's.

WindowFundMDY-1x the moveDifferenceMDY moved about
1M Aug 31 – Sep 30, 2026+4.7%−4.2%+4.2%+0.5 pts10%
3M Jul 1 – Sep 30, 2026+7.1%−5.6%+5.6%+1.6 pts12%
6M Apr 1 – Sep 30, 2026−4.0%+6.1%−6.1%+2.1 pts14%
1Y Sep 30, 2025 – Sep 30, 2026−6.9%+11.4%−11.4%+4.5 pts15%
3Y Sep 29, 2023 – Sep 30, 2026−24.4%+49.0%−49.0%+24.6 pts18%
Since launch Jan 4, 2010 – Sep 30, 2026−89.0%+502.3%not meaningful over this windownot meaningful over this window20%

MYY over each window to Sep 30, 2026. Every figure is an ETFIQ calculation. Source: ETFIQ.

Also against UMDD.

In plain words

Read the multiple against the whole window instead and −1 times MDY's −5.6% implies +5.6%, which makes MYY look 1.6 points over. 0.0 of that is daily compounding, which happens to any −1 times fund over the same path, and the rest is the fund. MYY aims to return -1 times MDY's move each day, then resets. Over one day it does that. Over longer, the daily results compound, so the total is not -1 times the period's move: in a market that falls and comes back it is reliably less, and in a steady run it can be more. MDY moved at 12% annualized over that window. That is what decides how far the two figures separate: the same fund on a calm underlying and a violent one is a different product.
Sets out to return-1 times the daily move of MDY, reset daily
Multiple a holder actually got over the window (ETFIQ)-1.28 times, against -1 stated
UnderlyingMDY
Segmentbroad index, US mid cap
Net assets (issuer page, as of Sep 30, 2026)$4m
Expense ratio (485BPOS XBRL, Sep 25, 2026)0.95%
LaunchedJan 4, 2010
Underlying volatility over the window (ETFIQ)12% annualized
MYY (ProShares Short MidCap400), leveraged ETFs fields as of Sep 30, 2026. Source: ETFIQ.
Returns are ETFIQ calculations from Tiingo end-of-day prices, distributions reinvested, measured against the underlying over exactly the same days. How these figures are computed

Questions people ask about MYY

Did MYY return -1 times MDY?
Over the window to Sep 30, 2026, MDY moved −5.6% and MYY returned +7.1%. −1 times that move is +5.6%, so the fund came out 1.6 points ahead of it.
Why does MYY not return -1 times over a year?
Because it resets daily. MYY aims at -1 times each day's move, and daily results compound. Over a run where the underlying falls and comes back, compounding a levered daily return leaves a holder behind what -1 times the period move would suggest; over a steady run in one direction it can leave them ahead. The longer the holding, and the more the underlying moves about, the further apart the two figures get.
Sources and dates
Prices, MYY and MDYTiingo end-of-day prices ↗
Fee, 0.95%SEC 485BPOS XBRL · Sep 25, 2026
Net assets, $4mIssuer page · Sep 30, 2026
IssuerProShares page for MYY ↗
All fund filingsFund filings on SEC EDGAR ↗
SourceSEC investment company series and class file, which lists every registered fund ↗

ETFIQ links to the documents behind every figure. It is not affiliated with any issuer, and a link is not an endorsement.

How these figures are computed →Standards and sources →Open data →
Cite this page

ETFIQ, MYY, leveraged ETFs, data as of Sep 30, 2026. https://etfiq.com/funds/myy

Open MYY live on ETFIQ

The label bar for MYY, redrawn every trading night. Free to use with the credit link.

Free to use with attribution; the underlying files are at Open data.

Stated multiple
What the fund sets out to return against its underlying, each day. A fund at 2x aims to return twice the underlying’s daily move, and an inverse fund at -2x aims to return twice it in the opposite direction.
Daily reset
The fund starts each day aiming at the multiple again, from wherever it now stands. It is the mechanism that makes these funds behave as they do, and the reason the stated multiple applies to a day rather than to a holding period.
Compounding
Daily results multiply together rather than adding up. Two days of the multiple is not twice the multiple, and over a run of days the difference between the two grows with how far the underlying moves about.
Decay
What compounding costs a holder when the underlying falls and rises back to where it started. The underlying is level and the fund is down; the more violently it moved, the further down.
Difference against the stated multiple
The fund’s return minus the stated multiple times the underlying’s return, in percentage points. The one figure that says whether a holder got what the fund’s own multiple describes.
Every term used here, defined in full on the leveraged ETFs vocabulary page. →
3rd of 6 leveraged ETFs on MDY, by where they finished against their stated multiple→5th of 6 leveraged and inverse ETFs by net assets→ProShares: every fund ETFIQ covers→