Why a Slow 50% Drop Pays More in SOXS Than a One-Day Crash

SOXS is a daily product.

Every session it resets, targeting −3× the semiconductor index’s move that day. Hold it past the close and you are no longer getting what the name implies.

The −3× applies only to a single close-to-close period. Over a week, a month, or a quarter the return you actually receive depends on the path the index took to get there, not the net move.

Path 1: the index drops 50% in one day

The math takes one line. The index returns −50%. SOXS returns −3 × −50%, so +150%. A $10,000 long position returns $25,000.

There is no compounding, because it all happened on one day.

Path 2: the index drops 5% a day for 10 days

In this situation, the index does not fall 50%. Losing 5% per day for 10 sessions compounds to 0.95¹⁰, which is −40.13%.

SOXS gains 15% on each of those days. That compounds to 1.15¹⁰, or +304.6%.

SEMICONDUCTOR INDEX vs SOXS: 10 consecutive sessions at −5% per day

Session	Semiconductor index price	SOXS price
Start	$100.00	$100.00
1	$95.00	$115.00
2	$90.25	$132.25
3	$85.74	$152.09
4	$81.45	$174.90
5	$77.38	$201.14
6	$73.51	$231.31
7	$69.83	$266.00
8	$66.34	$305.90
9	$63.02	$351.79
10	$59.87	$404.56

A $10,000 long position becomes $40,456. The index fell 40.13% and SOXS gained 304.6%. The realized multiple on the cumulative index move is 7.59×, not 3×.

If that same −40.13% had occurred in a single session instead, SOXS would have returned 3 × 40.13%, or +120.4%. The long position would be worth $22,038.

The index ended up at the same number, and the SOXS return differed by $18,418, purely from the path of the drop.

Same destination, completely different payoffs

To make the comparison clean, force both paths to end with the semiconductor index down exactly 50%.

A one-day crash of −50% produces a +150% day in SOXS. A steady −6.697% every day for 10 sessions also leaves the index at −50%. SOXS compounds to +523.8%.

Same net move in the index. One path pays 3.5 times more than the other.

SOXS return for two paths that both end with the index down 50%

Path	Index daily	Sessions	Index cumulative	SOXS cumulative	$10,000 becomes
One-day crash	−50.00%	1	−50.00%	+150.0%	$25,000
Ten-day slide	−6.697%	10	−50.00%	+523.8%	$62,384

Hypothetical, before fees, expenses and financing.

The daily reset compounds the position

Every close, SOXS resets its exposure to −3× its current net assets. That single rule drives the entire difference.

Start with $100 of NAV. The ETF is short $300 of the index. The index drops 6.697%. The short position gains $20.09, so NAV rises to $120.09. To stay at −3×, the ETF must now be short $360.27. It adds to the short at the close.

The next day’s drop is applied to a larger book. Day three is applied to a still larger book. In a one-directional decline, profits are automatically reinvested into more short exposure every afternoon. The position grows geometrically with NAV.

The one-day crash never gets the chance. It earns 3× on the original exposure and stops.

The same rule works against you

The daily reset does not care which direction the index moves.

An index that rallies 50% in a single session would produce a −150% day in SOXS, which is terminal. An index that rallies 50% over 10 sessions at +4.138% per day takes SOXS down 73.4%. The ETF survives, but it now needs a +276% move just to get back to even.

When the index goes nowhere and chops sideways, SOXS still loses. 10 index sessions that alternate −5.00% and +5.263% leave the index exactly flat. SOXS ends those 10 sessions down 14.8%. Nothing happened to semiconductors and nearly 15% of the SOXS position is now gone.

Ten-session outcomes for SOXS across four index paths

Index path	Index cumulative	SOXS cumulative
−6.697% daily	−50.00%	+523.8%
−5.00% daily	−40.13%	+304.6%
Alternating −5.00% / +5.263%	0.00%	−14.8%
+4.138% daily	+50.00%	−73.4%

Note:

The one-day 50% crash is a thought experiment. Circuit breakers halt the market at −7%, −13% and −20%.