Buying a stock used to require a phone call to a broker. Today, it takes about five minutes online. But speed and simplicity have also made it easy to skip the steps that actually matter. Choosing the right account type, understanding how orders work, and knowing what you are buying before you buy it. This guide covers the process from open to close, with the detail an active trader actually needs.
What a Stock Is
A stock is a fractional ownership interest in a publicly traded company. When a company sells shares on the open market, it is raising capital by dividing itself into tradeable units. As a shareholder, the value of those units rises and falls with the market’s assessment of the company’s future earnings.
There are two primary types: common stock and preferred stock. Common stock is what most traders mean when they say “stock.” It carries voting rights, variable dividends (if any), and the most price volatility. Preferred stock pays a fixed dividend on a predetermined schedule and has a higher claim on company assets if the company fails, but it trades more like a bond and is rarely the focus of active traders.
Within common stock, the further classifications worth knowing are growth stocks (companies expected to grow earnings above market average, rarely paying dividends), value stocks (trading at a discount to peers on earnings, sales, or dividend metrics), and blue-chip stocks (large, established companies with long operating histories and consistent dividends). Small-cap stocks carry more volatility and greater upside than large-caps. That volatility is what day traders are specifically looking for.
Step 1: Choose the Right Broker and Account Type
The broker is not just a platform. The broker determines what order types are available, how fast execution happens, what data feeds are included, and what it costs to trade. Getting this decision wrong is an expensive mistake to undo.
Cash Account vs. Margin Account
A cash account lets a trader buy stocks using only deposited funds. No leverage. Once capital is deployed, those funds are unavailable until the trade settles, which happens the next business day (T+1). Cash accounts cannot be used to short stocks. They are the standard starting point for new traders who want to stay disciplined about size and risk.
A margin account extends credit against the deposited balance. For accounts at $25,000 or more, standard intraday leverage is 4:1, meaning $25,000 in capital controls $100,000 in buying power. Margin accounts also allow short selling. The $25,000 threshold is not the broker’s preference. It is a FINRA rule that applies to any account classified as a “pattern day trader.” A trader who executes 4 or more day trades within 5 business days using a margin account will be classified as a pattern day trader and must maintain that $25,000 minimum. Falling below it suspends day trading privileges until the balance is restored.
For traders who are undercapitalized and want to day trade, a cash account sidesteps the PDT rule entirely. The tradeoff is that settled funds must be available before placing each trade, which limits how many trades can be made in a session.
What to Look For in a Broker
For active traders, the relevant differentiators are execution quality, platform tools, order routing control, and data access. Commission-free trading is standard at most major online brokers for US-listed equities. What separates brokers for active traders is whether they support direct access routing, Level 2 market depth data, hotkeys for rapid order entry, and real-time scanning tools. A retail investor buying and holding index funds has different needs. The broker that is right for one type of trader is often a poor fit for the other.
Step 2: Fund the Account
Opening a brokerage account requires a Social Security number, a government-issued ID, and a bank account for the initial transfer. Most online brokers complete the process in under 15 minutes. Funding by ACH transfer from a linked bank account typically takes 1 to 3 business days. Some brokers allow instant buying power on a portion of pending deposits.
The right amount to fund with depends on the account type and intended strategy. Margin account and day trading privileges require at least $25,000. A cash account can be opened and funded with any amount, though many active strategies require enough capital to weather volatility without being fully exposed on a single position.
Step 3: Research Before Buying
The question is not just “what stocks are worth buying” but “what information should the decision be based on.” For an investor holding a position for months or years, the relevant research is the company’s earnings trajectory, balance sheet, competitive position, and valuation relative to peers. Annual reports, 10-K filings, and earnings call transcripts are the primary sources. Most online brokers surface this data directly on their platforms.
For a day trader, the research process is different. The questions are: Why is this stock moving today? What is the catalyst? How does the float compare to current volume? What is relative volume doing? A stock with a small float, a real news catalyst, and relative volume of 5x or more is the kind of setup that generates intraday momentum. A stock moving without a catalyst is less predictable and harder to trade with conviction.
For swing traders, the analysis sits between those two approaches. Chart structure, trend direction, and whether the stock is in a sector with current momentum all factor in, alongside enough fundamental context to know the stock is not at risk of a collapse before the trade plays out.
No research method removes risk. A well-researched position can still lose. The point is to make decisions based on documented reasons, not on impulse or social media chatter.
Step 4: Decide How Many Shares to Buy
Position sizing is where most new traders make their first serious mistake. Buying a large position in a single stock concentrates risk. Buying such a small position that a big move in the stock does not materially affect the account makes the exercise academic.
A practical starting point: define the maximum dollar amount willing to be at risk on a single trade, then work backward from the entry price and the stop level. If the entry is $20.00 and the stop is $19.50, the risk per share is $0.50. A trader willing to risk $500 on the trade can buy 1,000 shares. That is the position size. The stop does the work, not the number of shares.
Many brokers now offer fractional shares, which allows participation in high-priced stocks without deploying a full share’s worth of capital. A stock trading at $1,500 per share can be purchased in dollar amounts rather than round lots. This is more relevant to long-term investors than to day traders, who typically need full shares to use standard lot-based order routing efficiently.
Step 5: Choose an Order Type
This is where execution actually happens. Two order types cover the vast majority of situations: market orders and limit orders.
Market Orders
A market order executes immediately at the best available price. Execution is guaranteed. Price is not. In a liquid stock with a tight spread, the difference between the quoted price and the filled price is negligible. In a thinly traded or fast-moving stock, slippage can be significant. Market orders are available during regular market hours from 9:30am to 4:00pm ET.
Market orders are appropriate when getting into or out of a position immediately matters more than the exact price. For long-term investors buying large-cap stocks in normal conditions, slippage risk is minimal. For active traders in volatile, thinly traded small-caps, market orders carry real execution risk.
Limit Orders
A limit order specifies the price at which the order will be filled. A buy limit order will not execute above the set price. A sell limit order will not execute below it. The tradeoff is that execution is not guaranteed and if the price never reaches the limit, the order goes unfilled.
Limit orders are the standard tool for active traders. They are available during all sessions: pre-market (typically starting at 4:00am ET), regular hours, and after-hours. They prevent overpaying in a fast market and allow precise entry at a planned level.
Stop Orders
A stop order triggers when a stock reaches a specified price, then executes as either a market or limit order. Used correctly, stops automate the exit when a position moves against the trader, limiting losses without requiring manual intervention. The risk with a stop-market order is that in a fast-moving or gapping stock, the execution price may be well below where the stop triggered. A stop-limit order sets the stop trigger and a minimum execution price, but if the stock gaps through the limit, the order may not fill at all.
Step 6: Execute the Trade
Once an order type is selected and the position size is confirmed, the trade is placed through the broker’s platform. Review the order details before submitting: the ticker symbol, the direction (buy or sell), the number of shares, the order type, and the price conditions.
After the order executes, settlement happens the next business day (T+1). The shares will appear in the account, and the portfolio value will reflect the position. Any unrealized gain or loss is not locked in until the position is sold.
If a market order is placed after regular hours (after 4:00pm ET), it will not execute until the next morning’s open. Limit orders placed outside market hours will queue and execute during the next session if the price conditions are met.
Understanding What Happens After the Buy
Owning a stock does not end the decision-making. The question shifts from “should I buy” to “should I hold, add, or sell.”
For long-term investors, the answer is usually to hold through volatility unless the original thesis has changed. A stock dropping 10% in a week is not automatically a reason to sell if the underlying business is performing as expected.
For active traders, the exit is as planned as the entry. The stop level is set before the trade is placed. The target is identified based on the chart structure and risk/reward ratio. The trade is managed to those levels, not improvised based on how the price feels.
Taxes are the third consideration most new buyers ignore. Stocks held for more than one year qualify for long-term capital gains rates, which are lower than ordinary income rates for most taxpayers. Stocks sold in under a year are taxed at ordinary income rates. For active traders running dozens of trades per week, tax treatment is a real cost that affects net returns. Consult a tax professional for guidance specific to trading volume and income level.
Frequently Asked Questions
What is the minimum amount needed to buy stocks?
Most online brokers have no minimum deposit for a standard brokerage account. Fractional shares allow purchases with as little as $1 at some brokers. The practical minimum depends on strategy. Day trading with a margin account requires maintaining $25,000 to avoid pattern day trader restrictions.
What is the difference between a market order and a limit order?
A market order executes immediately at the current best available price, guaranteeing execution but not price. A limit order specifies a maximum buy price or minimum sell price, guaranteeing price but not execution. Limit orders are standard for active traders who need precise entries and exits.
Can stocks be bought outside of normal market hours?
Yes. Most online brokers support pre-market and after-hours trading using limit orders. Pre-market typically begins at 4:00am ET and after-hours runs until 8:00pm ET. Liquidity is lower during extended hours, spreads are wider, and price movement can be more erratic. Market orders are not available outside regular hours.
What is a pattern day trader?
A pattern day trader is any trader who executes 4 or more day trades (opening and closing the same position within a single trading day) within a rolling 5-business-day window in a margin account. FINRA requires pattern day traders to maintain a minimum of $25,000 in their margin account. Falling below that balance suspends day trading activity until the requirement is met again.
What is the difference between a stock and an ETF?
A stock represents ownership in a single company. An ETF (exchange-traded fund) holds a basket of securities (often dozens or hundreds of individual stocks) and trades on an exchange like a single stock. ETFs offer built-in diversification and are typically used by long-term investors. Active day traders focus primarily on individual stocks due to the larger intraday price movements that single-company catalysts can produce.