---
title: "US Trading Rules"
description: "Discover essential information about US stock market trading rules, including trading hours, settlement times, and key regulations. Stay informed to make better trading decisions."
slug: "UStradingrules"
locale: "en"
region: "sg"
region_label: "Singapore"
url: "https://longbridge.com/sg/en/support/topics/usmarket/UStradingrules.md"
updated_at: "2025-11-20T08:53:03.000Z"
category: "usmarket"
category_title: "US market"
references:
  related:
    - title: "OTC Trading/Pink Sheets FAQs"
      url: "https://longbridge.com/sg/en/support/topics/usmarket/otcfaq.md"
    - title: "What is the US stock order book?"
      url: "https://longbridge.com/sg/en/support/topics/usmarket/a8a5l9.md"
    - title: "US Stock Pre-Market and After-Hours Trading Rules"
      url: "https://longbridge.com/sg/en/support/topics/usmarket/USmarketquotes.md"
    - title: "Understanding Order Types"
      url: "https://longbridge.com/sg/en/support/topics/usmarket/USordertypes.md"
    - title: "What Is a Market Order?"
      url: "https://longbridge.com/sg/en/support/topics/usmarket/marketorder.md"
---

# US Trading Rules

[Table of Contents](https://longbridge.com/sg/en/support/toc.md)

The US stock market provides a flexible trading mechanism that supports T+0 trading (day trade) and pre-market, after-hours trading. It has no price limits, and the minimum trading unit is 1 share. Below is a detailed introduction.

## 1\. US Stock Market Trading Hours

**US Eastern Standard Time (EST)**

09:30 AM – 16:00 PM

**Singapore Standard Time**

10:30 PM – 05:00 AM

Standard Time

09:30 PM – 04:00 AM

Daylight Savings Time

> *Daylight Savings Time begins from the second Sunday in March and ends on the first Sunday of November each year. Standard Time begins from the first Sunday in November and ends on the second Sunday of March each year.*

## 2\. US Stock Trading and Settlement Mechanism

**Day Trading**  
Day trading means buying and selling a batch of securities within a day. Day trading is often referred to as T+0 trading. Longbridge accounts can engage in unlimited day trading.

**Clearing Rules**  
US stocks are subject to a T+1 closing system under which the clearing and closing process is not completed until the next business day after the transaction.

## 3\. Minimum Board Lot Size and Price Limits for US Stocks

The minimum board lot size for US stocks is 1 share (fractional trading is currently not supported), and there is no single-day price limit.

## 4\. Minimum Stock Tick Size

Minimum stock tick size: USD 0.0001 for stocks trading under USD 1 and USD 0.01 for stocks trading above USD 1.

## 5\. Are Pre-Market and After-Hours Trading Supported?

Longbridge supports the Pre-Market and After-hours trading of the US stocks outside of the standard trading hours. The Long Bridge trading hours for all US stock markets are stipulated as follows:

**Pre-market trading hours for US stocks**

4:00 a.m. - 9:30 a.m. (ET)

Singapore (Daylight Savings Time):   
4:00 p.m. - 9:30 p.m.

Singapore (Standard Time):   
5:00 p.m. - 10:30 p.m.

**After-hours trading hours**

4:00 p.m. - 8:00 p.m. (ET)

Singapore (Daylight Savings Time):   
4:00 a.m. - 8:00 a.m.

Singapore (Standard Time):   
5:00 a.m. - 9:00 a.m.

**After-hours trading hours for US stocks on half-day trading days**

1:00 p.m. - 5:00 p.m. (ET)

Singapore (Daylight Savings Time):   
1:00 a.m. - 5:00 a.m.

Singapore (Standard Time):  
2:00 a.m. - 6:00 a.m.

**Key takeaways:**

-   Trading hours
    -   Regular trading: 09:30–16:00 ET (SGT for 21:30–04:00 EDT; SGT for 22:30–05:00 EST).
    -   Pre-market and after-hours: 04:00–09:30 ET (pre-market), 16:00–20:00 ET (after-hours).
-   Core rules
    -   Day trade: unlimited T+0 trades permitted (buy and sell the same stock within one day).
    -   Settlement system: clearing and settlement on T+1 (completed on the first working day after the trade).
    -   Price unit: minimum change of USD 0.0001 for stocks priced below USD 1; minimum change of USD 0.01 for stocks priced above USD 1.
-   Special restrictions
    -   There is no limit on price fluctuations, and the stock price can fluctuate freely.
    -   The minimum trading unit is 1 share (fractional shares trading is not supported for now).

**Disclosures**

*This article is for reference only and does not constitute any investment advice.*

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> **Disclaimer**: This article is for reference only and does not constitute any investment advice. Content provided by [Longbridge](https://longbridge.com).