Bid-Ask Spreads and Execution Slippage: Keeping an Evidence Diary in Bangladesh

Memory is a poor witness when something goes wrong with an account. This article treats bid-ask spreads and execution slippage on Binance, OKX, Bybit or Bitget as something to document, in Bangladesh: short dated notes, screenshots without secrets, and a record of where each piece of information came from. A small diary like this makes later questions far easier to answer calmly. The price shown on a chart is not necessarily the price you will get, and the gap between them is a real cost that never appears on the fee schedule.

What belongs in the diary

A useful entry has four parts: the date, the screen or page you looked at, what it said in your own words, and what you decided. Avoid copying passwords, codes or full addresses into the notebook. If you take a screenshot, crop out balances and identifiers you would not want a stranger to see, and store it in a folder named by month.

After each trade, compare the average fill price with the price you saw just before confirming. Keep a short note of the difference. Over a few weeks the notes show which pairs, sizes and times of day cost you most, which is more useful than any general rule.

Measuring your own execution

The order book in your exchange app shows how much volume sits at each price level. Before a larger trade, look at how far the price would need to move to fill your size. If your order would eat through many levels, consider splitting it or using a limit order, accepting that it may not fill completely.

The spread is the gap between the highest price buyers offer and the lowest price sellers accept. In actively traded pairs it is usually narrow; in less popular pairs it can be wide. Every immediate buy pays the ask and every immediate sell receives the bid, so a wide spread is a cost even before any fee is charged.

How slippage appears in a fill

Spreads tend to widen during sudden news, at quiet hours, around listing events and when liquidity providers step back. Placing a market order in those moments can produce surprisingly poor fills. If timing is not urgent, waiting for calmer conditions is often the simplest way to reduce costs.

Small pairs with low activity can show attractive prices on the chart that are impossible to trade in size. A last trade price may be hours old. Always look at the live bid and ask and the depth behind them, not just the chart, before assuming you can buy or sell at a given level.

Keeping notes useful months later

Diaries fail when they become too detailed to maintain. Limit each entry to a few lines and review the whole notebook once a quarter. Delete duplicates, mark anything that turned out to be wrong, and add a one-line summary at the top of each month. That summary is what you will actually read when you need it.

Risk boundary: Bangladesh Crypto Guide

Digital assets are volatile and derivatives can amplify losses. This website has no login, wallet connection, deposit form or customer-support chat. A referral link only records attribution; it does not guarantee access, pricing, rewards, approval or investment results. Availability can differ by residence, legal entity and product, so no regional access is assumed from language or branding alone.

Scenario checkpoint

• Look at order book depth to see how far your size would move the price.
• Compare the average fill price with the price you saw before confirming and note the gap.
• Test any price-protection setting with a small order before relying on it.
• Read the quote on convert features and compare it with the order book at the same moment.
• Keep a dated note for each change, written in your own words, with no passwords, codes or recovery words inside it.