To make your first investment, you'll need to open a brokerage account. Picking the best discount broker isn't easy, but we think the decision can be simplified by focusing on the most important factors. Below, we'll take a look at E*TRADE and TradeStation to show you how they compare to one another on features that are important to long-term investors.

Trading costs and commissions

Although there is more to a brokerage than its trading costs, it's important to know what you'll pay to make a trade. The table below compares E*TRADE's and TradeStation's published commission prices by various types of investments.

Broker

Stocks/Options

ETFs

Mutual funds

E*TRADE

$9.99 per trade + $0.75 per options contract

$9.99 per trade

$19.99 per purchase

TradeStation

$8.99 per trade + $0.70 per options contract

$8.99 per trade

$14.95 per purchase

Source: Company websites.

For most trades, the difference in cost is pretty marginal at about $1.00 per trade. Some investors will qualify for lower trading costs thanks to special offers, volume-based commission discounts, and the availability of funds that can be bought and sold for free.

Commission-free ETFs and NTF Funds

If you like funds and prefer to keep costs low, you might find that you can invest in many of your favorite funds without paying a transaction fee. Here's a summary of commission-free ETFs and no-transaction-fee mutual funds provided by each broker.

Broker

Commission-free ETFs

NTF Mutual funds

E*TRADE

100+ (WisdomTree, Deutsche Bank, and Global X)

2,500+

TradeStation

None

None

Source: Company websites.

As a reminder, any investment that isn't on a broker's fee-free lists will result in a trading commission. Therefore, it's not all about how many funds are available for free, but which funds are available for free. Notably, E*TRADE has more fee-free funds, but TradeStation has lower commissions on all other ETFs and mutual funds.

Account minimums

E*TRADE and TradeStation both require that investors meet initial deposit requirements. E*TRADE has a minimum of $500, whereas TradeStation requires $5,000 to open a traditional account and $5,500 to open an IRA account. 

You'll find that many brokers reward you for depositing more than the minimum. Learn more about special offers for ordinary brokerage accounts, as well as special offers for IRA accounts.

Trading platform

We here at The Motley Fool believe that a long-term strategy is the best investment strategy. Because we tend to hold stocks for years, we aren't traders, and don't really care about fancy charting or the look of a candlestick chart.

Frankly, the "quality" of a trading platform usually has a lot to do with personal preference and opinion. If a platform is important to you, give TradeStation and E*TRADE a run for their money with a demo account. If trading isn't your thing, you'll be pleased to find that making a trade is pretty simple with any online discount broker.

International stocks and ADRs

You don't need to hop on a plane to invest in foreign companies. TradeStation and E*TRADE make it possible to invest in foreign companies through American Depositary Receipts (ADRs). In addition, you can buy ETFs and mutual funds that hold foreign stocks.

If you want to buy companies that are listed directly on international stock markets, neither TradeStation nor E*TRADE currently offer that capability. Only a handful of discount brokers offer that functionality.

E*TRADE and TradeStation both allow for investing in foreign companies through ADRs. Image source: Getty Images.

Research quality and tools

Discount brokers have a reputation for cutting corners on research and support in order to deliver lower commission costs, but that's becoming less true with each passing day. In fact, both brokers offer fundamental and technical screens for stocks and funds.

E*TRADE offers research from S&P Capital IQ and Morningstar, for example. TradeStation provides a number of proprietary publications, including its Morning Market Briefing each trading day, in addition to weekly stocks and ETF reports. Depending on your needs, you can find plenty to like about free tools provided by either broker to complement your investment strategy.

Mobile app

Your cellphone can also act as your trading desk thanks to mobile trading apps. Here's how each broker's users and clients rated their iOS and Android apps (as of 12/14/2016).

Broker

Apple App Store

Google Play

E*TRADE

2.0 stars

4.0 stars

TradeStation

4.0 stars

4.5 stars

Source: Relevant app stores.

E*TRADE or TradeStation: a discount broker for your needs

An individual investor can find plenty to like about either brokerage. E*TRADE's commission-free fund selection might win over fund investors. TradeStation's lower options prices might win over the cost-focused options investor. Realistically, the "best" broker really and truly depends on your particular portfolio and style.

To be clear: The Motley Fool doesn't endorse any particular broker. Check out Fool.com's Broker Center for current special offers for brokerage accounts, as well as the IRA Center for deals on IRA accounts.