thinkorswim is Charles Schwab’s platform suite for trading and analysis. Its options tools include risk profiles and simulated trades. Schwab also offers an international account route. Check your country, account type and product permissions before choosing a live setup; software access and trading eligibility are separate checks.

Where did this platform come from?

Schwab’s announcement of 14 May 2024 confirms completion of the final Ameritrade client conversion. thinkorswim is now offered as a Schwab suite, with desktop, web and mobile versions. Their features differ: a desktop analysis workflow is not automatically available in the same form on every device. Use the current documentation for your actual platform and account.

Analyze and paperMoney: what do these tools model?

The Analyze tab models an options position’s profit and loss under assumptions about price, date and implied volatility. Its expiration curve differs from the theoretical value before expiry. A displayed probability, for example a hypothetical 70%, is a model output; it is not an observed 70% win rate of your trading strategy. Check the selected positions, signed quantities, strikes and expiry before changing the price or volatility inputs.

paperMoney uses virtual funds and simulated executions. Use it to rehearse quantities, order types, partial fills and the resulting position list. A fill in the simulator does not prove that the same price, queue position or costs would be available live. In thinkScript, AddOrder adds hypothetical strategy orders and signals, by default at the next bar’s open. Those strategies do not send real orders; separate live conditional-order functions require their own configuration.

What sets thinkorswim apart
Options analysischains with Greeks, Analyze tab, risk profile
Probability conetheoretical price range under model assumptions
paperMoneyvirtual funds and simulated execution
thinkScriptown indicator and scanner language
Costno separate platform charge; standard trading pricing applies

After one-leg assignment, reconcile every instrument

A count of “two legs” alone cannot check a spread. In our example you hold 1 long call 100, 1 short call 105 and 0 shares. Each is a standard American-style contract for 100 shares. You receive confirmation of early assignment of the short call only. Assume the account report records share delivery by opening a short stock position, while the other leg remains unexercised.

Scroll sideways to see the full diagram

Short-call assignment changes the instrument listBefore assignment: one long call 100, one short call 105 and zero shares. Only short-call assignment is confirmed. Afterward: one long call 100, zero short calls 105 and minus 100 shares. The long call is unexercised.One confirmed eventEarly short-call assignmentStandard contract: 100 sharesBEFOREAFTER1 long call 1001 long call 1001 short call 1050 short calls0 shares−100 sharesThe long call remains an option.Do not record exercise without an event.
The arrow connects the short-call obligation with the stock position. Merely being in the spread does not convert the remaining long option into shares.

After this event the holdings are 1 long call, 0 short calls and −100 shares. The long call still exists and affects the portfolio; do not record automatic exercise. Reconcile symbol, expiry, strike, direction and quantities of options and shares separately in Analyze and the account report. That list lets you assess the current position rather than a two-option combination that no longer exists.

Assumptions: Hypothetical standard US equity options; not adjusted contracts or every option type. Short-call assignment is already confirmed before expiry. The long call is unexercised and no other account action occurs. We show instrument types and quantities only, without calculating P/L, cash, margin or costs. Official material: Schwab: options-assignment risk; Schwab: standard multiplier and the seller's obligation.

And what about forex access?

Schwab’s forex service is available through the thinkorswim desktop, web and mobile platforms. It requires an eligible brokerage account and a separate forex application, with forex provided by Charles Schwab Futures and Forex LLC. Verify residence and product eligibility for that specific service; access to another Schwab account or to paperMoney does not establish live forex permission.

Check country, account and product eligibility

Schwab has an international account opening route that begins with country selection. The available accounts, products and required documents depend on that country and the application. Consult the current international process rather than assuming every non-US resident needs a US address or that all EU residents are excluded. The international platform page alone does not establish that a particular applicant is eligible for every product.

Account and product checks
Platformthinkorswim, a Schwab suite
Countrycheck the international country selector
Accountconfirm current eligibility and documents
Forexseparate product application and permissions
Simulationdoes not establish live trading permission

How to use thinkorswim for learning and analysis

Reproduce a small, explicitly hypothetical call vertical in Analyze: buy one call with strike 100 for USD 6 per share, sell one call with strike 105 for USD 3, same underlying and expiry. Assume a standard multiplier of 100 shares per contract, no other positions, no costs and no early exercise or assignment. The net debit is (6−3) × 100 = USD 300. If both legs remain intact until expiry, P/L is 100 × [max(S−100, 0)−max(S−105, 0)]−300.

Own expiry model; S is the underlying share price, all P/L in USD
S at expiryOne long 100 / one short 105
90−300
100−300
1030
105+200
110+200

For those assumptions, the largest expiry loss is USD 300, the largest gain is USD 200 and break-even is 103. This is our arithmetic example, not a quote, recommendation or assertion that every spread has those limits. Before expiry the risk curve can change with time and volatility. Execution costs alter the result, and assignment can change the instruments held.

Now change only the short quantity from one call to two at the same illustrative premium. The entry debit becomes (6−2 × 3) × 100 = USD 0, but the position is a 1:2 ratio rather than the previous vertical. Its expiry P/L is 100 × [max(S−100, 0)−2 × max(S−105, 0)]. At S=105 it is +USD 500; at 110 it is zero; at 115 it is −USD 500. Above 105 it equals 100 × (110−S), so the loss has no finite bound as S rises.

A zero net premium does not make this position risk-free. Check the quantities before relying on a bounded curve copied from the 1:1 position. The existing assignment diagram covers a different, confirmed event: with only the short call assigned and the long call unexercised, reconcile one long option and −100 shares. Do not use an intact two-option expiry formula for that new holding list. Eligibility, margin, exercise and assignment require separate checks.

How does it compare with other platforms for your account?

  • thinkorswim — options analysis and simulated trading; live access depends on account and product eligibility.
  • MetaTrader 4 and MT5 — compare the actual broker’s instruments, account permissions, data and automation environment.
  • TradingView — compare charting, subscription limits and the supported connection to your broker.
  • NinjaTrader and MultiCharts — compare systematic-testing workflows, supported connections and the requirements of your chosen account.

If you want specifics, start with our MT4 versus MT5 comparison, and for charting see the piece on TradingView versus MT5. The instruments themselves are explained in our guide to currency options from the ground up, and the wider tooling landscape is covered in our platforms section.

What to do tomorrow

  1. Check the official country selector, account requirements and permissions for the product you intend to trade. Use the international application route where applicable; do not infer eligibility solely from holding, or lacking, a US address or taxpayer number.
  2. Recreate the fictional 1:1 spread in Analyze, then change only the short quantity to two. Record the expiry date, selected legs and model inputs; compare the bounded and unbounded tails.
  3. Before writing an option, review the profit-and-loss profile of the whole position, including costs and the consequences of exercise or assignment. A short uncovered call can have unlimited loss, so a finite “maximum loss” cannot be assumed for every option strategy.
  4. Compare brokers and platforms that accept your residence and support your intended product. Check costs, permissions and simulation limitations before choosing an everyday charting or trading workflow.