Learn

⌂Dashboard◈Learn

Practice

⌁Charts◷Replay↻Review

My learning

▥Stats☆Bookmarks⌕Search✦AI

Learning principle

Understand risk before practising decisions.

Trade ButyFree · Neutral
👤 Log in
📚Learn📈Markets⏮Replay✎Review🔍Search🤖AI👤 Log in
Trade Buty

A free & neutral trading education platform for Chinese speakers worldwide. Structured courses (learn) × live charts & replay (practice).

⚠️ Risk notice: All content is for study and research only and does not constitute investment advice. Markets are risky.

Navigate

LearnMarketsReplaySearchAIStatsPrivacy PolicyContent from kline-butyFeedback
© 2026 sun1090 · MIT LicenseContent from kline-buty

On this page

  • What Is a Market Maker
  • Quoting Obligations
  • Earning the Bid-Ask Spread
  • Inventory Management
  • How Market Makers Profit — and Lose
  • Revenue Model
  • How They Lose
  • Market Makers' Effect on Price: Volatility Absorber vs Amplifier
  • Normal Markets: Volatility Absorber
  • Extreme Markets: Volatility Amplifier
  • Why Bids Vanish During Crashes
  • What Liquidity Is: Depth / Width / Resilience
  • Liquidity and Slippage: What $10,000 Buys You
  • Worked Example: A $10,000 Market Order
  • Slippage vs Commissions
  • The Liquidity Trap: Hard to Get Out
  • How to Avoid Liquidity Traps
  • "Liquidity Black Holes": When Bids Vanish Instantly
  • March 12, 2020 (Crypto's "312")
  • May 2022 Luna Collapse
  • March 2020 US "Circuit-Breaker Week"
  • Implications for Your Trading
  • Choose Instruments and Hours Wisely
  • Market Orders vs Limit Orders
  • Three "Check Liquidity First" Questions
  • Summary

Chapter progress

12 · Market Ecosystem

The earlier chapters taught you to "read the rules and read the charts." This chapter asks you to step back and take a m

0/7 lessons0%

Next chapter →

13 · Financial History→

The previous twelve chapters taught you how to "read the market, build a system, and manage risk"; this chapter teaches

Learn/12 · Market Ecosystem
Lesson 02/2 / 7 lessons

02 · Market Makers & Liquidity

A deep dive into market-maker mechanics and the liquidity system — understand your true trading costs and where slippage comes from.

📖 ~10 min read
On this page▾
  • What Is a Market Maker
  • Quoting Obligations
  • Earning the Bid-Ask Spread
  • Inventory Management
  • How Market Makers Profit — and Lose
  • Revenue Model
  • How They Lose
  • Market Makers' Effect on Price: Volatility Absorber vs Amplifier
  • Normal Markets: Volatility Absorber
  • Extreme Markets: Volatility Amplifier
  • Why Bids Vanish During Crashes
  • What Liquidity Is: Depth / Width / Resilience
  • Liquidity and Slippage: What $10,000 Buys You
  • Worked Example: A $10,000 Market Order
  • Slippage vs Commissions
  • The Liquidity Trap: Hard to Get Out
  • How to Avoid Liquidity Traps
  • "Liquidity Black Holes": When Bids Vanish Instantly
  • March 12, 2020 (Crypto's "312")
  • May 2022 Luna Collapse
  • March 2020 US "Circuit-Breaker Week"
  • Implications for Your Trading
  • Choose Instruments and Hours Wisely
  • Market Orders vs Limit Orders
  • Three "Check Liquidity First" Questions
  • Summary

You've heard it said: "There's always a counterparty on the other side of the screen." That confidence comes from market makers and the whole liquidity system. A market without liquidity is a swimming pool with no water — jumping in is easy; climbing out is another matter.

This article covers two things thoroughly: who provides your liquidity (market makers), and how liquidity quality determines your true cost of execution (slippage).

⚠️ Risk Warning

Descriptions of market-making mechanics, liquidity metrics, and historical events here are teaching generalizations. Past crashes do not guarantee similar future events, and liquidity can deteriorate sharply at any time as conditions change. All figures are illustrative, not real-time levels for any instrument. Markets carry risk; invest with caution; nothing here constitutes investment advice.


What Is a Market Maker

A market maker is a professional trader who continuously provides two-sided quotes (simultaneously posting a bid and an ask), usually licensed by exchanges with incentives such as fee rebates.

text
The market maker posts both sides:
  bid (buy price)   ask (sell price)
   ──────────────┬──────────────
    buys what you sell    sells what you buy

You sell at market → filled at bid → market maker buys
You buy at market  → filled at ask → market maker sells
The spread is the market maker's gross margin

Quoting Obligations

  • Market makers commit to maintaining both buy and sell quotes through most of the session (minimum quoting time, minimum order size, and non-cancellation ratios are set by exchange rules).
  • In return, exchanges grant makers reduced fees or even rebates — every dollar a market maker earns is essentially a liquidity subsidy from the platform plus the bid-ask spread.

Earning the Bid-Ask Spread

  • Spread = ask − bid. For example, if BTC is quoted at 60,000.1 / 60,000.2, the spread is $0.10.
  • The goal is "buy low, sell high, turn fast": tiny per-trade margins (0.01%–0.05%) multiplied by volume.
  • Higher volume and lower volatility make earnings steadier — so market makers naturally love quiet markets.

Inventory Management

  • Market makers accumulate inventory (buying more than selling = long inventory; the reverse = short inventory).
  • Bigger inventory means bigger risk: if price falls after buying, the inventory loses immediately.
  • So market makers are always hedging: taking offsetting positions in futures/options and dynamically adjusting quotes to bring inventory back to neutral.

How Market Makers Profit — and Lose

Revenue Model

Income SourceDescription
Bid-ask spreadEarned on each two-sided fill
Fee rebatesExchange incentives for posting orders (maker rebates)
Micro-profit on order flowReading microstructure to anticipate short-term direction and adjust quotes
Market-making rebate programsPlatforms pay back fees by quoting time/volume (common in crypto)

How They Lose

Loss SourceMechanismExample
Inventory riskWrong-way inventory moves against themAdverse news hits right after buying; inventory is trapped
Being "squeezed"Big money deliberately lifts offers; maker forced to stop outPool operator keeps buying; maker's short inventory gets liquidated
Information asymmetryCounterparty knows news the maker doesn't and reprices firstMakers still quoting old prices just before earnings/regulatory news
Sudden volatilityShock events gap prices instantly beyond quote rangesBlack-swan events; fills far outside quoted levels
Withdrawal runsLiquidity evaporates; inventory can't be unwoundIn crashes, makers want to sell but find no buyers

💡 Key Insight: Market Makers Are Risk Merchants, Not Philanthropists

Key insight: market makers are not charitable "market stabilizers" — they are risk merchants. When risk-reward turns lopsided, they withdraw without hesitation — exactly why bids vanish during big drops.


Market Makers' Effect on Price: Volatility Absorber vs Amplifier

Normal Markets: Volatility Absorber

  • With orders resting on both sides, market makers naturally "catch" retail's chase-and-dump flow:
    • Someone panic sells → filled at the bid, price stabilizes;
    • Someone FOMO buys → filled at the ask, pressure eases.
  • Effect: short-term volatility is smoothed, keeping prices closer to "fair value." That is liquidity's value — you can enter or exit at any moment near the market price.

Extreme Markets: Volatility Amplifier

  • When price trends hard one way, maker inventory goes rapidly long/short and risk exposure spirals → widening spreads loses fills, tightening spreads loses money. Ultimately they choose:
    1. Massively widen spreads (bids far below, asks far above);
    2. Cut quoted size;
    3. Pull bids entirely, leaving only asks (or pull everything).
  • Result: bids vanish → sellers fill ever lower → price accelerates down → triggering more stop-losses → a self-reinforcing decline.

💀 In Extreme Markets Makers Pull Their Bids, Triggering Self-Reinforcing Declines

In extreme markets, market makers pull their bid side outright, leaving only asks (or withdrawing everything). Bids vanish in seconds → sellers fill ever lower → price accelerates down → more stops trigger → the fall feeds itself. Makers are not philanthropists but risk merchants — when risk-reward breaks, they leave at once.

Why Bids Vanish During Crashes

text
Panic selling → maker short-inventory piles up fast → inventory risk maxes out
   ↓
Makers cancel bids / only quote bids far below market
   ↓
Market sells hit an ever-thinner book, slicing straight through levels
   ↓
Price waterfall → leveraged stop-outs fire → more selling (negative feedback)
  • Crypto's "wick hunts" (flash crashes far below fair value followed by recovery) mostly originate here: bids drained within moments, price slicing below everyone's psychological level.
  • Both March 12, 2020 ("312") and the May 2022 Luna collapse showed textbook "vanishing bids" — see "Liquidity Black Holes" below.

What Liquidity Is: Depth / Width / Resilience

ElementMeaningPlain Language
DepthCumulative order volume around current price"How thick is the book" — how large an order it absorbs without moving price
WidthSize of the bid-ask spread"How wide is the gap" — tighter spreads mean cheaper entry/exit
ResilienceHow quickly price recovers after a large-order shock"After you pierce the water surface, does it close back up?"
text
                 Width (small spread = good)
         ┌────────────────────────┐
  Ask wall  ▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓  ← Depth (thick book = good)
         └────────────────────────┘
         ↑ If price snaps back quickly after a large buy → resilient

A liquid instrument is deep (absorbs big capital), narrow (tight spread), and resilient (recovers quickly after being pierced).


Liquidity and Slippage: What $10,000 Buys You

Slippage = actual fill price − expected fill price. The worse the liquidity, the bigger the slippage.

Worked Example: A $10,000 Market Order

Assume BTC trades at $60,000 with ideal book depth:

InstrumentBook Condition$10k Market BuySlippage
BTC (major)$0.1 spread, 10–50 BTC per levelFill ≈ 60,000.2≈ 0.0003% (~$2)
Major altcoin0.5% spread, tens of thousands USD per levelFill 0.1%–0.3% higher$10–30
Obscure small cap2%–5% spread, sparse bookFill 1%–5% higher, sometimes slicing multiple levels$100–500+
Low-liquidity futuresThin book, few counterpartiesFill 0.5%–2% higher$50–200+

Conclusion: the same $10,000 might slip under $1 in BTC but eat hundreds of dollars in small caps — a round trip costing 1%–10%. Trivial for small accounts, fatal for large capital and frequent traders.

Slippage vs Commissions

  • Most beginners watch commissions and ignore slippage. In practice: for high-frequency or large trades, slippage often dwarfs fees.
  • Market orders have uncontrolled slippage; limit orders have none (but may not fill) — that's the essence of the market-vs-limit choice.

The Liquidity Trap: Hard to Get Out

A "liquidity trap" describes instruments you can apparently trade but where real capital cannot easily exit:

ScenarioSymptom
Small caps / junk tokensEasy to buy, impossible to sell; any decent sell order craters the book
Small-cap stocksA few million daily turnover; buying 1% pins the limit-up, no buyers when you flee
Low-volume futuresFar-month contracts near delivery have paper-thin books
Halts / limit locksOne-way limit-up: can't buy; one-way limit-down: can't sell
Wick hunts in extremesStops execute at extreme prices inside a liquidity vacuum

Classic disaster: an altcoin does $3M daily volume; you buy $50k (1.7% of daily volume). When you try to sell, total visible bids are only $20k — your order slams price from 1.0 to 0.9, turning "paper profit" into "real loss."

How to Avoid Liquidity Traps

  • Only trade instruments meeting average daily turnover / turnover-ratio thresholds (major crypto; A-share names trading above ¥100 million/day).
  • Slice large orders, use limits, scale in and out; if you need cash urgently, trade during the most liquid hours.
  • Avoid mini-tokens "up 100% today" — their liquidity is often fake book depth posted by the operator themselves.

"Liquidity Black Holes": When Bids Vanish Instantly

A liquidity black hole is what happens in extreme markets when bid and ask sides both disappear within moments; price loses support and gaps down like a waterfall.

March 12, 2020 (Crypto's "312")

  • Backdrop: global COVID panic, repeated US circuit breakers, crypto collapsing alongside.
  • Process: BTC fell from ~$8,000 to below $4,000 in a day; spot and futures books were drained of bids almost completely, futures saw cascading liquidations, and platforms including Binance suffered brief outages.
  • Aftermath: several exchanges were accused of "pulling the plug" or deliberately amplifying leverage liquidations during the crash — recurring regulatory and community controversy (see 08-Pitfalls↗, platform risks).

May 2022 Luna Collapse

  • Backdrop: Terra's UST (algorithmic stablecoin) lost its peg; LUNA supply hyperinflated.
  • Process: UST depegs → panic selling → LUNA fell from $80 to zero; DeFi lending liquidations exploded in chains, and LUNA/UST books on centralized exchanges went to zero bids instantly.
  • Lesson: in a stablecoin depeg or algorithmic "death spiral," liquidity simply does not exist — by the time you want to "buy the dip," the bids are long gone.

March 2020 US "Circuit-Breaker Week"

  • Circuit breakers fired day after day; bids vanished simultaneously across ETFs, stocks, bonds, and gold — even "safe havens" fell, because everyone was selling assets for cash.

Implications for Your Trading

Choose Instruments and Hours Wisely

DimensionAdvice
InstrumentPrefer majors (BTC/ETH, CSI 300 constituents, active contracts); avoid mini-tokens and penny stocks
TimingAvoid extremes and overnight gaps; in 24-hour crypto, Asia-Europe handoffs and major data releases are volatile
DirectionLiquidity is best trading with the trend; bottom-fishing against it often buys into "no bids" phases

Market Orders vs Limit Orders

Order TypeProsConsBest For
Market orderGuaranteed fill, fastUncontrolled slippage; wick-hunted in thin booksLiquid majors, small positions
Limit orderNo slippage, controlled costMay not fill; may miss big movesLarge positions, illiquid instruments, ranges

Practical combo: split large positions across 3–5 limit orders; use market orders for stops (better to pay slippage than miss the exit); in violent markets place limits where they'll "obviously fill," not glued to the touch.

Three "Check Liquidity First" Questions

  1. Is this instrument's average daily turnover enough for my planned position to enter and exit smoothly?
  2. How many book levels will my order slice through? (Open the depth view and check sizes from best bid/ask through level five.)
  3. If the market reverses suddenly, will my stop fill at a reasonable price?

Summary

text
Liquidity = your hidden trading cost
  ├─ Depth: can the book absorb your order?
  ├─ Width: what does the spread cost you?
  └─ Resilience: does price recover after being pierced?

Market maker = liquidity provider, and also a risk merchant
  ├─ Normal times: absorbs volatility so you come and go freely
  └─ Extremes: pulls orders to survive → bids vanish → liquidity black hole

Remember one sentence: never go heavy where there is no liquidity. Before liquidity determines how much you can make, it determines whether you can get out.

💀 Never Go Heavy Where There Is No Liquidity

Never take heavy positions where there is no liquidity. Before liquidity decides how much you can earn, it decides whether you can get out. Market makers are not philanthropic "market stabilizers" but risk merchants — once risk-reward turns lopsided they withdraw instantly, which is exactly why bids vanish during crashes.


⚠️ Risk Warning

All prices, book depths, and slippage figures here are illustrative teaching data; real levels vary enormously across exchanges and sessions. Historical crashes ("312," Luna, circuit-breaker week) need not repeat, but "liquidity can vanish in an instant" is a standing risk in every market. Leveraged positions in illiquid instruments can be blown through stops or liquidated within minutes by extreme prints. Markets carry risk; invest with caution; nothing here constitutes investment advice.

📝 市场生态篇 · 随堂测

3 concept questions · instant grading

📖 Done reading? See the real market

Find the concepts from this lesson on the live chart — understand before you continue.

Open live chart →
🤖Ask AI: 02 · Market Makers & Liquidity→

Related lessons

  • →01 · A Panorama of Market Participants
  • →03 · Recognizing Market Manipulation
  • →04 · The Information Ecosystem
  • →05 · Exchange Business Models
  • →06 · High-Frequency Trading in Depth

Next

03 · Recognizing Market Manipulation

→