THE STABLECOIN THAT WAS SUPPOSED TO STAY AT $1, THEN FELL APART
It was called a "stablecoin." Its entire purpose was to stay worth $1. Then the system designed to protect that $1 started working against itself.
In 2022, there was a cryptocurrency called TerraUSD, or UST.
The promise was simple:
1 UST = $1
No matter what happened in the crypto market.
No matter whether Bitcoin went up or down.
No matter how much speculation was happening.
UST was supposed to remain stable.
But there was a problem.
There wasn't a pile of dollars sitting in a bank account backing every UST.
The system depended heavily on another cryptocurrency:
LUNA.
And when confidence disappeared, the relationship between the two tokens turned into a vicious cycle.
IT WASN'T A NORMAL STABLECOIN
There are different ways a cryptocurrency can attempt to maintain a stable value.
Some stablecoins use assets such as cash, bank deposits or short-term government securities as reserves.
UST used a very different approach.
It was an algorithmic stablecoin.
Its system attempted to maintain the $1 price through an automated arbitrage mechanism involving LUNA.
The basic idea was:
UST below $1
↓
Users could exchange UST for approximately $1 worth of LUNA.
↓
UST supply decreased.
↓
LUNA supply increased.
↓
Arbitrageurs had an incentive to participate.
↓
UST should move back toward $1.
On paper, it looked elegant.
THE SYSTEM NEEDED PEOPLE TO BELIEVE IN LUNA
This is where the design became much more complicated.
Imagine UST falls to:
$0.99
Someone could theoretically buy it for 99 cents and use the Terra mechanism to obtain $1 worth of LUNA.
That creates a potential $0.01 arbitrage opportunity.
If enough people do it, the system should push UST back toward $1.
But there was an important assumption underneath everything:
Someone had to be willing to buy the LUNA.
As long as LUNA had a strong market value, the mechanism could appear to work.
If confidence in LUNA disappeared, the whole structure became much more fragile.
THEN ANOTHER PRODUCT MADE UST EVEN MORE ATTRACTIVE
The Terra ecosystem had a lending platform called Anchor Protocol.
It attracted users by offering yields that reached around 20% on UST deposits.
That created an extremely attractive proposition:
Hold UST
↓
Keep your value close to $1
↓
Earn a very high yield
For people looking for returns in crypto, it was hard to ignore.
UST's supply grew rapidly.
By early 2022, TerraUSD had reached a peak market capitalization of approximately:
$18.7 billion
making it the third-largest stablecoin at the time, according to the Bank for International Settlements.
THEN UST LOST THE NUMBER THAT MATTERED MOST
In May 2022, UST began moving below its $1 target.
At first, that didn't necessarily mean the system was finished.
Stablecoins can temporarily move away from their target.
But this time, confidence kept deteriorating.
People wanted to get out.
And the mechanism designed to restore UST required issuing more LUNA.
THE SYSTEM STARTED FIGHTING ITSELF
This was the critical problem.
Imagine millions of dollars of UST being converted into LUNA.
The system creates more LUNA.
More people then try to sell that LUNA.
The market price of LUNA falls.
Now even more LUNA must be created to represent the same dollar value.
↓
UST falls
↓
More LUNA is created
↓
LUNA falls
↓
Even more LUNA is required
↓
Confidence falls further
↓
More UST is sold
It became what the BIS described as a death spiral.
THE $1 PEG COLLAPSED
The mechanism couldn't restore confidence quickly enough.
UST's price collapsed.
LUNA collapsed alongside it.
The BIS reported that UST fell from $1 to just a few cents within days, eventually approaching zero.
The SEC later described the May 2022 event as UST de-pegging from the U.S. dollar while UST and related tokens plunged toward zero.
A cryptocurrency designed to behave like:
$1
had effectively become:
almost nothing.
THE STRANGE PART WAS THE ORIGINAL IDEA
The idea wasn't simply:
"Let's create a cryptocurrency that says it's worth $1."
The system tried to create stability without relying on traditional dollar reserves.
That was the attraction.
If it worked, Terra's ecosystem could theoretically create a digital dollar-like asset without maintaining a conventional pile of dollars or equivalent reserves.
But that also meant the system's stability depended heavily on:
market confidence
LUNA's value
arbitrage activity
liquidity
and continued participation.
When those assumptions broke down simultaneously, the mechanism couldn't save itself.
IT DIDN'T JUST HURT UST
The collapse spread through the wider crypto market.
The BIS reported that Tether, the largest stablecoin at the time, briefly fell to around $0.95 and experienced more than $10 billion of outflows in the following weeks.
Investors also moved money toward other stablecoins, including USDC.
Terra's collapse had become a broader confidence event.
THEN REGULATORS STARTED LOOKING CLOSER
The collapse didn't end the story.
The U.S. Securities and Exchange Commission later brought enforcement action against Terraform Labs and its founder, Do Kwon, alleging fraud and violations involving crypto asset securities. The SEC said Terraform and Kwon had misled investors about UST's stability, among other allegations.
In April 2024, a federal district court found Terraform Labs and Kwon liable for fraud and unregistered securities offerings; they later agreed to pay $4.5 billion to resolve the SEC's case.
The legal proceedings became a separate chapter of the Terra story.
THE BIGGER BUSINESS LESSON
The fascinating part of TerraUSD isn't simply:
"A cryptocurrency crashed."
Thousands of cryptocurrencies have crashed.
The interesting part is that Terra attempted to engineer stability itself.
It tried to create a financial product whose value was supposed to remain stable through incentives and market mechanisms rather than traditional reserves.
For a while, the system grew enormously.
Then the assumptions supporting it broke.
A $1 PROMISE CAN BE EXPENSIVE TO KEEP
The word "stable" can sound reassuring.
But stability isn't created by a name.
A financial system has to have a mechanism that can survive stress.
In Terra's case:
UST needed LUNA
↓
LUNA needed market confidence
↓
Market confidence weakened
↓
UST holders rushed to exit
↓
More LUNA was created
↓
LUNA collapsed
↓
UST lost its support
The mechanism became part of the problem.
MAACAT PERSPECTIVE
TerraUSD was built around a powerful idea:
What if you could create a digital dollar without actually holding a dollar for every token?
For a while, the market accepted the idea.
Then the market tested it.
And that is where the difference between a mechanism that works in normal conditions and a mechanism that survives a crisis became painfully clear.
The $1 target was simple.
Keeping the system behind the $1 target was not.
