thinkScript price types

Mark Price in thinkScript

PriceType.MARK requests the platform mark quotation. Learn how to use it with the close function, its chart limitations, and how it differs from last, bid, and ask.

Customize it with AI View the thinkScript code

MarkPriceStudyexcerpt

input priceType = PriceType.MARK;

plot MarkPrice = close(
    priceType = priceType);
MarkPrice.SetDefaultColor(Color.CYAN);

PriceType.MARK

close()

intraday only

Constant: PriceType.MARK
Used with: close(priceType = ...)
Chart limit: Non-Forex: intraday, up to 15 days

Direct answer

What the mark price is and when to use it

The mark series is a platform quotation reference. The API reference does not specify one universal mark formula for all instruments. It does not prove intrinsic value, freshness, or an available execution price.

In thinkScript, you reference it with PriceType.MARK and the close function. The Learning Center notes that for non-Forex symbols, this price type is only supported on intraday charts with a time interval not greater than 15 days.

Code examples

Plot and compare the mark price

Plot the mark price

Plot

# Plot the mark price with PriceType.MARK
input priceType = PriceType.MARK;

plot MarkPrice = close(priceType = priceType);
MarkPrice.SetDefaultColor(Color.CYAN);
MarkPrice.SetLineWeight(2);

AddLabel(yes,
    "Mark: " + AsText(MarkPrice),
    Color.WHITE);

Use an input for priceType so you can switch between mark, last, bid, and ask from the study settings without editing the source.

Compare all price types

Compare

# Compare price types
def markPrice = close(priceType = PriceType.MARK);
def lastPrice = close(priceType = PriceType.LAST);
def bidPrice = close(priceType = PriceType.BID);
def askPrice = close(priceType = PriceType.ASK);

AddLabel(yes, "Mark: " + AsText(markPrice), Color.CYAN);
AddLabel(yes, "Last: " + AsText(lastPrice), Color.WHITE);
AddLabel(yes, "Bid: " + AsText(bidPrice), Color.GREEN);
AddLabel(yes, "Ask: " + AsText(askPrice), Color.RED);

Display mark, last, bid, and ask side by side in chart labels. Useful for spread analysis on intraday charts.

Price type comparison

Mark vs. last, bid, and ask

thinkScript supports four PriceType constants. Each returns a different price quotation from the close function.

PriceType	Description	Common use
PriceType.MARK	Platform-provided mark quotation, not a guaranteed fill	Futures and options pricing
PriceType.LAST	Most recent traded price	Equities and general charting
PriceType.BID	Highest current buy order price	Selling and spread analysis
PriceType.ASK	Lowest current sell order price	Buying and spread analysis

Primary sources

Official thinkScript references used here

Frequently asked questions

What is the mark price in thinkorswim?

PriceType.MARK requests the platform-provided mark series. The API reference does not establish a universal calculation formula for every instrument. Treat mark as a quotation reference, not intrinsic value or a guaranteed execution price.

How do I reference the mark price in thinkScript?

Use PriceType.MARK with the close function. For example, close(priceType = PriceType.MARK) returns the mark price. You can also make it configurable with an input: input priceType = PriceType.MARK, then close(priceType = priceType).

What are the chart limitations for PriceType.MARK?

According to the thinkorswim Learning Center, PriceType.MARK is only supported on intraday charts with a time interval not greater than 15 days for non-Forex symbols. On daily or longer charts, or on charts with a longer intraday range, the mark price may not be available.

How does mark price differ from last price?

LAST requests trade-based prices; MARK requests the mark series. Either can be unavailable or stale depending on the feed and chart context. A difference does not establish an executable arbitrage.

Can I use PriceType.MARK for options?

Yes, but be aware of the chart limitation. For non-Forex symbols, PriceType.MARK only works on intraday charts with a time interval of 15 days or less. BID and ASK share the same documented non-Forex chart restriction, so averaging them does not bypass it.

Can Pineify generate a thinkScript study that uses the mark price?

Yes. Describe what you want to display in plain English. The Pineify thinkorswim AI Coding Agent can draft the source, but does not compile it in thinkorswim or establish data availability. Check the function calls and test the output on a supported chart.

Build a mark price study with AI

Describe what you want to display in plain English. The Pineify thinkorswim AI Coding Agent can draft the source. Check the syntax in thinkorswim and inspect whether your chart actually supplies MARK data.

Open the thinkScript AI agent

This page is for educational and informational purposes. It does not provide investment advice, predict future prices, or guarantee trading results.