Free trading lessons that start with how a price is made
zolqivo is a free educational project for adults across Europe who want to understand what happens between clicking a button and owning a position. Watch the introductory video, read five open lessons and test the arithmetic yourself. No account, no payment, and no financial services of any kind.
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Lesson one, chapter by chapter
Any quote you see has two sides. The bid is the highest price someone is currently willing to pay; the ask is the lowest price someone is currently willing to accept. A buyer who wants an immediate fill pays the ask, a seller who wants one receives the bid.
Behind the two numbers sits an order book: a list of waiting buy orders below the current price and waiting sell orders above it. The best bid and best ask are simply the top line on each side. When those orders are taken or cancelled, the quote changes.
Each line of the book shows a quantity. A small order fills against the top line. A large one can use up that line and continue to the next, worse price. The average fill then differs from the quote that was on screen, which is why depth matters as much as price.
The lesson closes with three questions to ask of any quote: how wide is the gap between bid and ask, how much quantity sits at those prices, and how quickly do they change. None of them says whether to trade; all of them describe what a trade would cost.
Who runs zolqivo
A small editorial team that explains market mechanics and sells nothing.
We write the lessons, record the video and answer every message ourselves. The material is free to read and watch, there is no paid tier and nothing on this page asks for your money or bank details. When we use numbers, they are hypothetical and labelled that way.
Who writes
The zolqivo editorial team. Lessons are reviewed by a second editor before publication.
What you get
One video lesson with transcript, five written lessons, a glossary, a self-check quiz and articles, all open without registration.
What we do not do
No investment advice, no trading signals, no brokerage, no account management, no commissions.
How it is funded
zolqivo is an independent educational project. It sells no financial products and is not paid to mention any.
Five free lessons, readable in any order
Each lesson explains one mechanism, works through a small hypothetical example and ends with something you can check yourself.
An order is not a wish to buy or sell; it is a precise instruction with conditions. A market order says: fill now at whatever price is available. A limit order says: fill only at this price or better, and wait if that is not possible. The first gives certainty of execution and uncertainty of price, the second the opposite.
Most confusion comes from forgetting the second half of that trade-off. A limit order may never be filled, and a market order in a thin market may be filled further from the quote than expected.
Hypothetical example: the ask is 50.20 with 100 units available, and the next line is 50.35. A market order for 150 units fills 100 at 50.20 and 50 at 50.35, an average of 50.25.
Check it yourself
Find any public quote screen and note the bid, the ask and the quantity shown at each. Then work out what a market order twice that size would pay on average if the next line were one step worse.
Every position is opened and later closed, and both steps cost something. The spread is paid implicitly: buying at the ask and selling at the bid loses the gap even if nothing else moves. Commissions, currency conversion and overnight financing come on top, depending on the product.
Costs look small per trade and large per year. The habit worth building is to calculate them as a share of the position before anything else.
Hypothetical example: bid 99.90, ask 100.10, commission 2 per side. Opening and closing 10 units at an unchanged price costs 2.00 in spread plus 4.00 in commission, 6.00 on a position of about 1,000.
Check it yourself
Take any instrument page and write down every cost it lists. Sort them into costs paid once, costs paid per trade and costs paid per day held.
Leverage means controlling a position larger than the money set aside for it. That set-aside money is the margin. With leverage of 10, a margin of 1,000 controls an exposure of 10,000, and every price change applies to the full 10,000.
The consequence is arithmetic, not opinion: a 1 percent move against the position removes 10 percent of the margin. A 10 percent move removes all of it. Many providers close positions automatically before that point, at a price the holder does not choose.
Hypothetical example: margin 500, leverage 20, exposure 10,000. A 2.5 percent adverse move equals 250, half of the margin.
Check it yourself
Without a calculator, work out the adverse move that would remove a whole hypothetical margin at leverage 5, 10 and 30. Then compare your result with the third question of the self-check further down.
A stop order waits until a price is reached and then becomes an ordinary market order. It limits how long a position stays open, not the exact price at which it closes. In a fast market the fill can be worse than the stop level; this difference is slippage.
A gap is the extreme case: the price jumps from one level to another with no trading in between, for example over a weekend or after an announcement. A stop inside the gap is filled at the first available price after it.
Hypothetical example: stop at 48.00, the market closes at 48.60 and opens at 46.90. The stop fills near 46.90, not 48.00.
Check it yourself
Read the order-type section of any provider's documentation and find the sentence that says whether a stop is guaranteed. Note what, if anything, a guarantee costs.
Material about markets often shows results without the conditions that produced them. Ask three questions of any claim: over what period, after which costs, and how many similar attempts were left out. Screenshots of single wins answer none of them.
Backtests deserve the same care. A rule tuned on past data until it looks good will describe the past well and the future poorly. Honest material states its limits, shows costs and does not promise outcomes.
Hypothetical example: a method shown with ten winning trades out of ten says nothing if a hundred trades were taken and the ninety others are not shown.
Check it yourself
Pick any piece of trading content you have seen recently and write down which of the three questions it answers. Then do the same for one of our lessons.
A trading day, stage by stage
What happens to orders from before the open until settlement. Opening hours differ between venues, so the stages are described without clock times.
Before the open
Orders queue up
Orders sent before trading starts wait in the book. Many venues then run an opening auction: instead of matching orders one by one, they look for the single price at which the largest quantity can change hands.
Opening auction
One price for many orders
When the auction ends, every matched order fills at the same price. That price can sit noticeably away from the previous close, which is one of the ways a gap appears.
Continuous trading
Orders meet one at a time
For most of the session each incoming order is matched against the book as it arrives. Spreads tend to be narrowest in this phase and displayed quantities largest, though both shift through the day.
Around an announcement
The book thins out
Shortly before scheduled data or company results, many participants pull their orders. Spreads widen, and a market order can travel further through the book than it would an hour earlier.
Closing auction
The reference price is set
Many venues end the session with a second auction. Its result often becomes the official closing price, the figure that fund valuations and account statements refer to.
After the close
Positions carry over
A position held past the close is exposed to whatever happens overnight. For leveraged positions this is also the moment overnight financing is charged or credited.
One or two days later
Settlement
Money and instruments change hands and ownership is recorded. Until then a purchase is an obligation between the parties, not yet a holding on the register.
Owning an instrument or holding a leveraged contract on it
The same price move affects the two very differently. Read the table question by question, or switch to one column at a time.
Owning an instrument compared with a leveraged contract on its price
Question
Owning the instrument
Leveraged contract on its price
What is actually held
The instrument itself, recorded in the holder's name or through a custodian
An agreement with a provider that settles price differences; nothing underlying is owned
Money committed for an exposure of 10,000 (hypothetical)
10,000
A margin, for example 1,000 at leverage 10
Effect of a 5 percent price fall (hypothetical)
Value drops by 500, a twentieth of the money committed
A loss of 500, half of the 1,000 margin
Holding overnight
No financing charge; custody fees may apply
Overnight financing on the full 10,000, charged or credited each day
Rights attached
Dividends or coupons and, for shares, often a vote
Usually cash adjustments only, no vote
How the position ends
When the holder sells
When the holder closes it, or automatically when the margin runs short
Largest possible loss
The money committed
The margin and, depending on the provider and the rules that apply, possibly more
All figures are hypothetical and chosen only to show the mechanism. Real conditions differ between products, providers and countries.
Check your understanding
Four short questions on the lessons. Nothing is recorded or sent anywhere; the answer and its reasoning appear as soon as you check.
The glossary, read in context
Fourteen terms from the lessons, placed in one short hypothetical case. Select a highlighted word and its definition appears beside the text.
A hypothetical case
A hypothetical reader opens a quote screen and sees the a few cents apart; that gap is the . The underneath holds little quantity, so is thin, and prices jump more than usual because is high today. The reader compares a with a and chooses the limit. A is added to bound a loss, in the knowledge that can carry the fill past it. The intermediary charges a on each side. With , the reader would also have to hold , could receive a after losses and would pay for every night the position stays open.
Select any highlighted term to read its definition.
Bid and ask Market structure
The highest price currently offered by buyers and the lowest price currently asked by sellers.
Spread Costs
The gap between the bid and the ask. Opening and immediately closing a position at the same moment loses this amount.
Order book Orders
The list of waiting buy and sell orders at each price, with the quantity at each level.
Liquidity Market structure
How easily a quantity can be traded without moving the price much. Thin liquidity means wider spreads and more slippage.
Volatility Market structure
How much and how quickly a price tends to move. It describes movement, not direction.
Market order Orders
An instruction to buy or sell immediately at the best price available. Execution is near certain, the price is not.
Limit order Orders
An instruction to trade only at a stated price or better. It may wait in the order book and may never be filled.
Stop order Orders
An order that stays inactive until a trigger price is reached and then becomes a market order.
Slippage Risk
The difference between the expected price of an order and the price at which it is actually filled.
Commission Costs
A fee charged per trade by an intermediary, either fixed or as a share of the trade value.
Leverage Risk
Controlling an exposure larger than the money set aside. It multiplies the effect of every price move.
Margin Risk
The money that must be held to open or keep a leveraged position.
Margin call Risk
A demand to add money when losses reduce the margin below a required level, often followed by automatic closing.
Overnight financing Costs
A charge or credit for holding a leveraged position past the end of a trading day, based on the full exposure.
Articles from the editorial desk
Longer pieces on markets, instruments and technology, written as background to the lessons.
Markets
Why the same order can fill at two different prices
Depth, timing and the queue at each price level explain most surprises at execution.
Two people sending the same market order a second apart can receive different prices. The quote they both saw was only the top line of the book, and the first order may have used it up.
Time of day matters too. Around the open and the close of a session, and around scheduled announcements, books often thin out and spreads widen. A limit order trades the risk of a poor price for the risk of no fill at all.
None of this is a flaw to exploit; it is the normal behaviour of a shared queue. Understanding it mainly helps to read execution reports without surprise.
Instruments
Shares, bonds and funds described by what the holder owns
A share is part ownership, a bond is a loan, a fund is a pooled portfolio. The risks follow from that.
A share gives part ownership of a company: a claim on what remains after everyone else has been paid, and often a vote. Its value depends on what others expect that claim to be worth.
A bond is a loan with an agreed schedule of payments. Its risks are that the borrower cannot pay and that its price falls when interest rates elsewhere rise.
A fund pools money from many holders and buys a portfolio. It spreads the risk of single holdings but keeps the risk of the market it invests in, and it charges ongoing costs that compound over time.
Startups
What a funding round measures and what it leaves out
A valuation in a private round is a negotiated price for a small slice, not a market price for the whole company.
When a young company raises money, it agrees a price per share with a small number of investors. Multiplying that price by all shares gives the headline valuation, even though most shares never traded at it.
Rounds often carry terms that matter more than the price: preferences in a sale, conversion rights, protections against later rounds at lower prices. Two rounds at the same valuation can mean very different things for earlier holders.
Stakes in private companies are hard to sell, may pay nothing for many years and can lose their entire value. Reading a round as a measure of success skips all of that.
Technology
What a language model does with a market headline
Text models summarise and classify news. They do not know what happens next, and their errors are confident.
A language model turns text into predictions about the next words. Given a headline, it can summarise it, translate it or label it as positive or negative in tone. That is useful for reading volume, not for knowing outcomes.
The model has no view of order books, positions or future events. It can also produce fluent statements that are wrong, with no signal that they are wrong.
Treat model output about markets as a draft written by a fast reader who cannot check sources. This article describes the technology; it does not recommend using it for trading decisions.
Questions readers ask
If your question is not here, the contact form below goes straight to the editors.
An editorial team that writes and reviews the lessons and articles. We do not present ourselves as advisers or as a firm offering financial services, and the contact details on this page are where you can reach us.
zolqivo is an independent educational project. It sells no financial products, takes no commissions and receives nothing for mentioning any provider; none are mentioned.
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