MRNA: a pandemic boom, a 90% bust, and this month's spike
The Market Wave Algorithm for Equities against Moderna in three windows. Buy and hold beaten in all three.
Moderna: the vaccine maker that rose 750% in a pandemic, lost 90% after it, and gained 177% in one day.
Why this case study, and why now
Moderna punished everyone. It punished the holders who bought the pandemic story near the top. It punished the sellers who gave up near $23. And on August 19 it punished anyone still waiting for a comfortable entry, by tripling before the open.
This study asks three questions, each with its own window and its own recipe of the Market Wave Algorithm for Equities.
What if you had turned it on this summer?
Strategy+338.6%
- Buy and hold
- +242.4%
What did this year actually pay?
Strategy+531.4%
- Buy and hold
- +399.4%
What happens across a full boom and bust?
Strategy+1,187%
- Buy and hold
- +165%
Every run starts from the same hypothetical $100,000 in cash and zero shares.
Backtested results. Past performance does not guarantee future results. For educational purposes only.
The subject
Moderna makes messenger RNA medicines. Its COVID vaccine made it one of the fastest growing companies in history, then one of the fastest shrinking. Revenue went from $19.3 billion in 2022 to $1.9 billion in 2025. Its pipeline, led by a personalized cancer vaccine with Merck, is what investors have been paying for ever since.
The price history is one of the wildest in the market.
- December 2018Moderna goes public at $23 and trades lower for a year.
- June 2020The stock sits near $58 as the first COVID vaccine trials read out.
- August 9, 2021All time high of $497.49. Fourteen months, more than eight times the money.
- 2022 to 2025Demand and revenue collapse. The stock loses more than 90% from the high and trades near $23 in 2025, its IPO price, seven years later.
- January 2026A 17% day on cost cuts and guidance, a run of nearly 87%, then a 34% slide into February on FDA setbacks and patent uncertainty.
- March 4, 2026A $950 million patent settlement ends the worst-case fear. The stock rises 16% to $58.
- August 19, 2026The Phase 3 melanoma trial with Merck succeeds. Moderna closes at $174.38, up 177% in one session, then falls 24% the next day. It trades near $150 today.
Here is the catch that matters for this study. Moderna made two fortunes and destroyed one in between. The investor who caught the first had to survive a 95% drawdown to see the second, and the investor who waited for the second had to buy a stock that had just tripled overnight.
The investor's dilemma
Moderna is a conviction test, and conviction is not a strategy. The stock sets up three failure modes that human investors handle badly.
Round trip riding
A holder from June 2020 watched $100,000 become roughly $850,000 by August 2021, then watched it fall below $40,000 by 2025. Paper wealth, gone, over four years of hoping for the next catalyst. The stock's best day in history did not get that investor back to the 2021 high.
The too high freeze
After the August 19 announcement, every entry looked like the top. Investors who waited for a pullback got one the next day, a 24% drop, and still had to buy at more than double the prior week's price.
The paper gain trap
In 2021 Moderna was a $190 billion company and every holder was rich on paper. Almost none of them sold. Realized profit is the only kind that survives a 90% decline.
Dollar cost averaging deserves credit here. It kept buying near $23 in 2025 when the consensus target was $30. But DCA has a structural cost: it buys blind, it never sells, and it never realizes a dollar.
A rules-based algorithm restores what Moderna takes away: a way to be paid on the way up without riding the whole way down.
The algorithm
The Market Wave Algorithm for Equities is Arch Public's algorithm for stocks. It does three things a human holder struggles to do at the same time.
Ride confirmed moves
It buys when price breaks above the wave with a buffer, and adds when the move holds. It does not need to know why the stock is moving.
Exit on rules, not nerves
It sells a set share of the position when a target is hit or the trend flips. It sold Moderna into the 2021 peak and into last week's spike.
Step aside in chop
When price sits inside the wave, it waits in cash. It sat out most of the 2022 to 2024 decline.
Every recipe in this study uses the same three levers: the wave scope (0.5 is micro, 20 is macro), the entry and exit thresholds, and the trade size. The weekly round trip uses a scope of 2 with both trend filters on, built to catch regime changes. The 2026 window uses a micro scope of 0.5 with a small exit threshold, built to bank a fast move. The summer window uses a macro scope of 18.5 that only buys below the wave, built to buy the dips of a stock already trending.
A macro scope of 18.5 that only buys below the wave, built to buy the dips of a stock already trending.
A micro scope of 0.5 with a small exit threshold, built to bank a fast move.
A scope of 2 with both trend filters on, built to catch regime changes.
Backtested results. Past performance does not guarantee future results. For educational purposes only.
“The fresh start”
June 1, 2026 to August 25, 2026 · Hourly chart · Macro recipe, buy the dips
Suppose you switched the algorithm on in June with $100,000 and no history in the stock. It ran to $87 in early July, fell back to $55, drifted for three weeks, then tripled on August 19. Buy and hold earned +242.4%, almost all of it in one day.
The algorithm bought the June dips, sold the July run near $70 to $80, bought again near $55, and sold most of the position into the spike above $160.
+338.6%
- Buy and hold +242.4%, outperformance +96.2 percentage points
- Ending value
- $438,640
- Realized profit
- $335,145
- Shares held
- 36 at $54.73 avg cost
- Cash
- $433,175
Backtested results on the hourly chart, valued August 25, 2026. Past performance does not guarantee future results. For educational purposes only.
“The 2026 scoreboard”
January 1, 2026 to August 25, 2026 · Four hour chart · Micro recipe, bank the move
Buy and hold earned +399.4%. Almost nobody got that number, because almost nobody held through February or bought before August 19.
The micro recipe took every leg: the January breakout, the February top, the July peak, the late July dip, and three sales into the August spike.
+531.4%
- Buy and hold +399.4%, outperformance +132 percentage points
- Ending value
- $631,444
- Realized profit
- $484,177
- Unrealized profit
- $47,266
- Shares held
- 494 at $56.99 avg cost
- Cash
- $556,025
Backtested results on the four hour chart, valued August 25, 2026. Past performance does not guarantee future results. For educational purposes only.
“The round trip”
June 1, 2020 to August 25, 2026 · Weekly chart · Regime recipe, trend filters on
This is the whole story. Buy and hold earned +165% over six years, most of them spent far below the 2021 peak.
The regime recipe rode the 2020 to 2021 run and sold most of the position near $440. It sat in cash through most of the decline, bought heavily near $25 to $30 in 2025, and was fully positioned before August 19.
+1,187%
- Buy and hold +165%, outperformance +1,022.1 percentage points
- Ending value
- $1,287,041
- Realized profit
- $438,933
- Unrealized profit
- $748,108
- Shares held
- 8,114 at $61.99 avg cost
- Cash
- $35,943
Backtested results on the weekly chart, valued August 25, 2026. Past performance does not guarantee future results. For educational purposes only.
Side by side
| The fresh start | The 2026 scoreboard | The round trip | |
|---|---|---|---|
| Window | Jun 1 to Aug 25, 2026 | Jan 1 to Aug 25, 2026 | Jun 1, 2020 to Aug 25, 2026 |
| Chart | Hourly | Four hour | Weekly |
| Recipe | Macro scope 18.5, buy below | Micro scope 0.5, sell above | Scope 2, trend filters on |
| Strategy return | +338.6% | +531.4% | +1,187% |
| Buy and hold | +242.4% | +399.4% | +165% |
| Outperformance | +96.2 pts | +132 pts | +1,022.1 pts |
| Ending value | $438,640 | $631,444 | $1,287,041 |
| Realized profit | $335,145 | $484,177 | $438,933 |
| Shares held | 36 | 494 | 8,114 |
| Avg cost basis | $54.73 | $56.99 | $61.99 |
| Cash | $433,175 | $556,025 | $35,943 |
All three from $100,000 and zero shares.
Backtested results. Past performance does not guarantee future results. For educational purposes only.
Why the results differ
The three scenarios are the same algorithm answering three different questions.
The fresh start asks: what if I start today, with no history and no conviction?
Answer: The macro recipe answers by buying dips below a long wave and selling strength. It does not need to know the cancer trial is coming. It only needs the stock to move.
The 2026 scoreboard asks: how much of a fast year can be turned into cash?
Answer: The micro recipe answers by selling half the position on every 3.2% target, over and over, so the spike pays out in pieces instead of on paper.
The round trip asks: what happens across a whole boom and bust?
Answer: The regime recipe answers by selling the 2021 top, waiting, and rebuilding at the 2025 bottom. That is the trade no human made.
Buy and hold answers every question with the same single decision, made once, then endured. Its result depends entirely on when that decision was made and whether the holder survived what came after.
The edge is not prediction. None of these recipes knew August 19 was coming. They were positioned by rules, paid by rules, and never had to be right about Moderna's future to be paid by its present.
Backtested results. Past performance does not guarantee future results. For educational purposes only.
The real lesson
- 01
Realized profit is the only kind that survives
Moderna holders were rich on paper in 2021. Rules that sell into strength turned that paper into cash, and cash does not draw down 90%.
- 02
You do not have to hold the whole way down to catch the way back up
The regime recipe sat out most of the collapse and still owned 8,114 shares when the trial read out. Stepping aside is a position.
- 03
Starting late is not a penalty
A recipe switched on in June, with no view on the stock, returned +338.6% by late August. The algorithm does not need a story. It needs a signal.
The client decision is which job you want done. Bank a fast move into cash, or build a low-basis position for the next big catalyst. The Market Wave Algorithm for Equities has a recipe for each, and Moderna just showed both.
Backtested results. Past performance does not guarantee future results. For educational purposes only.
A path forward
Arch Public runs the Market Wave Algorithm for Equities in your own brokerage account. Zero custody: your money never leaves your account. Full control: you choose the recipe, the size, and when to switch it off. Rules, not reactions: the algorithm does not read headlines, watch the pre-market, or fear the next day.
A buy and holder from June 2020 has +165% and six years of whiplash to show for it. The same $100,000 under the regime recipe has $1,287,041, a $61.99 cost basis, and $438,933 already realized.
What do you want your account doing the next time a stock triples overnight?
A buy and holder from June 2020
+165%
The same $100,000 under the regime recipe
$1,287,041
A $61.99 cost basis, and $438,933 already realized
The comparison that matters is the two short windows against the long one. In 2026 the algorithm turned a fast move into cash: $484,177 realized this year, $335,145 of it available to a recipe that started in June. Across six years it did the opposite job, building 8,114 shares at a $61.99 basis so that the August 19 announcement landed on a full position. Same algorithm. Different recipe, different job, and it beat buy and hold at both.