In what order are stocks bought/sold? If I put a sell limit price in immediately after buying a stock, will it be sold at that price before someone who watches the market and puts in a sell order the day it hits that price?

The deep research logic is organized as follows: 

Okay, let's tackle this question. The user is asking about the order in which stocks are bought and sold, specifically whether a sell limit order placed immediately after buying a stock will be executed before someone else who places a sell order when the price hits that target. 

First, I need to recall the basics of how stock exchanges operate. From the references, I remember that stock exchanges use order-driven markets, which prioritize price and time. The key here is understanding the priority rules for limit orders. 

Looking at reference 6, it mentions that orders are queued based on price, then time. So, a higher buy price or a lower sell price gets priority. If two orders have the same price, the one entered first (FIFO) comes first. 

The user's scenario involves placing a sell limit order right after buying. Let's say the user buys a stock at $50 and immediately sets a sell limit at $55. If the market price reaches $55, will the user's order execute before someone else who places a sell order at $55 when the price hits that level? 

According to the priority rules, the user's order was entered first. So, when the price hits $55, the user's order should be matched first because it's already in the order book. The other person's order, placed after the price trigger, would come later in the queue. 

But wait, there's a catch. If the user's order is a limit order, it's already in the order book waiting. When the price reaches $55, the user's order is at the top of the sell queue. The other person's order, placed after the price movement, would be a new order at the same price but later in time. So, the user's order should execute first. 

However, there's a consideration about the type of order. If the user uses a market order, it would execute immediately at the best available price, but that's not the case here. The user is using a limit order, which is price-priority. 

Also, some exchanges might have different rules. For example, NYSE uses a parity/priority model (reference 9), which allocates shares to all orders at the best price, not just the first one. But the user's question is about immediate execution after placing the limit order, so the general price-time priority applies unless specified otherwise. 

Another point is the possibility of partial fills. If the user's order is larger than the available buy orders at $55, only part of it might execute. But the user's main concern is whether their order gets priority, not the fill size. 

So, putting it all together, the user's sell limit order placed immediately after buying should be executed before someone else's sell order placed when the price hits that level, assuming the same price and the user's order was entered first. The key factors are price priority and time priority in the order book.

**Conclusion** 🎯
When you place a sell limit order immediately after buying a stock, your order will generally be prioritized over someone who later places a sell order at the same price when the stock reaches that level. This is due to the **price-time priority** mechanism used in most stock exchanges, where orders are matched based on the best price first and, in case of ties, the earliest time of entry.

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### **Analysis** 📊
#### 1. **Order Priority Rules**
Stock exchanges operate on a **price-time priority** system . Here’s how it works:
- **Price Priority**: Orders with better prices (higher buy prices or lower sell prices) are executed first.
- **Time Priority**: If multiple orders have the same price, the one entered earlier (FIFO) is executed first.

| Scenario | Your Order | Competitor’s Order | Execution Order |
|----------|------------|---------------------|-----------------|
| You place a sell limit at $55 immediately after buying | Sell Limit @ $55 (entered at Time A) | Competitor places a sell limit @ $55 when price hits $55 (entered at Time B) | **Your order executes first** |

#### 2. **Why Your Order Gets Priority**
- **Immediate Entry**: Your sell limit order is already in the order book when the stock price reaches $55.
- **Competitor’s Delay**: The competitor’s order is placed **after** the price trigger, making it later in the queue.

#### 3. **Exceptions to the Rule**
- **Market Makers**: Some exchanges allow market makers to jump the queue for liquidity purposes .
- **Exchange-Specific Rules**: Certain exchanges (e.g., NYSE’s parity/priority model) may allocate shares proportionally to all orders at the best price .

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### **Key Takeaways** 📌
- **Act Fast**: Placing a limit order immediately after buying gives you a head start in the queue.
- **Monitor Liquidity**: Ensure there are buyers at your target price to avoid partial fills or no execution.
- **Avoid Market Orders**: Limit orders provide price control but require patience.