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  • Nikhil Adithyan

Stock Market Sentiment Prediction with OpenAI and Python

Updated: May 4

An interesting exploration of the power of LLMs in stock analysis

Stock Market Sentiment Prediction with OpenAI and Python

Introduction: Prediction with OpenAI and Python

In today’s stock market, staying informed about news and events is crucial for making strategic decisions. Recognizing the impact of sentiment on market trends is essential to adjust strategies accordingly. The process begins with accessing vast amounts of market news available through various sources. Foremost among these are the requirements for data quality (such as the number of sources, data update rate, etc.) and ease of use.

Although the data is available online and easily accessible, one of the most convenient methods for our needs is to use an API endpoint to integrate market data and news directly into our code. There is a variety of financial data providers that offer API connections; they vary in the data packages, support approach, and quality of data they provide.

In this article, we are going to use the Stock Market and Financial News API provided by one of the Market Data providers named EODHD, which, in my opinion, boasts a great balance of quality and price. The API provides an endpoint for extracting insights from financial news, facilitating easy analysis of market sentiment. With its ease of use, users can query and retrieve news articles, enabling a dynamic assessment of the market’s positive or negative tones.

By showcasing the capabilities of the API, I aim to demonstrate its seamless integration into sentiment analysis, enabling us to make informed decisions based on prevailing market sentiments. In the fast-paced environment of the stock market, having access to such a resource ensures a more adaptive and strategic approach to investing.

Without further ado, let’s dive into the article.

Importing Packages

Let’s start with importing the required packages into our Python environment. We’ll be using three packages in this article which are Pandas for working with dataframes, eodhd for extracting data, and langchain for building the LLM model. Apart from these, we will also be using other secondary packages like config and re. Import all the necessary packages using the following code:

!pip install openai
!pip install langchain
!pip install eodhd
!pip install config

import re
import requests
import pandas as pd
import config as cfg
from eodhd import APIClient
from langchain.chains import LLMChain
from langchain.prompts import PromptTemplate
from langchain.chat_models import ChatOpenAI

Before importing, make sure to install the packages using the command line. Now that we have all the required packages imported into our Python environment, we can proceed to the next step which is activating the API key.

API Key Activation

It is essential to register the EODHD API key with the package in order to use its functions. If you don’t have an EODHD API key, firstly, head over to their website, then, finish the registration process to create an EODHD account, and finally, navigate to the ‘Settings’ page where you can find your secret EODHD API key. It is important to ensure that this secret API key is not revealed to anyone. You can activate the API key by following this code:

api_key = '<YOUR API KEY>'
api = APIClient(api_key)

The code is pretty simple. In the first line, we are storing the secret EODHD API key into api_key, and then in the second line, we are using the APIClient class provided by the eodhd package to activate the API key and stored the response in the client variable.

Note that you need to replace <YOUR API KEY> with your secret EODHD API key. Apart from directly storing the API key with text, there are other ways for better security such as utilizing environmental variables, and so on.

Extracting the Data

We are going to use the Stock Market and Financial News API by accessing the Python library provided by EODHD as follows:

resp = api.financial_news(s = "AAPL.US", from_date = '2024-01-01', to_date = '2024-01-30', limit = 100)
df = pd.DataFrame(resp) # converting the json output into datframe

Let me explain the parameters in the API:

  1. s: String. REQUIRED if parameter ‘t’ is not set. The ticker code to get news for.

  2. t: String. REQUIRED if parameter ‘s’ is not set. The tag to get news on a given topic. you can find the provided topic list on this page:

  3. api_token: String. REQUIRED. Your api_token to access the API. You will get it after registration.

  4. from and to: the format is ‘YYYY-MM-DD’. If you need data from Mar 1, 2021, to Mar 10, 2021, you should use from=2021–03–01 and to=2021–03–10.

  5. limit: Number. OPTIONAL. The number of results should be returned with the query. Default value: 50, minimum value: 1, maximum value: 1000.

  6. offset: Number. OPTIONAL. The offset of the data. Default value: 0, minimum value: 0. For example, to get 100 symbols starting from 200 you should use limit=100 and offset=200.

The data would look like this:

AAPL news data extracted using EODHD API

The output data has the following fields:

  • date: The date and time of the article are in ISO 8601 format.

  • title: The title of the article.

  • content: The full body of the article.

  • link: The link to the source.

  • symbols: The array of ticker symbols is mentioned in the article.

Cleaning the Data

Now this data is unclean and contains lots of line breaks and different commands. So we are going to clean them:

# funtion to clean the textual data
def clean_text(text):
    cleaned_text = re.sub(r'\s+', ' ', text)
    return cleaned_text.strip()

# Apply the replacement function to the entire column
df['content'] = df['content'].apply(clean_text)

Now we have applied it to all the data and we can move forward with our chatbot.


Now we will use Langchain to form an LLM chain with the OpenAI model.

llm = ChatOpenAI(model = "gpt-3.5-turbo",
                 openai_api_key = 'YOUR OPENAI API KEY', 
                 temperature = 0)

NOTE: You should replace YOUR OPENAI API KEY with your own OpenAI API key for the smooth functioning of the code without any errors.

This code snippet initializes the Language Model (LM) by instantiating GPT-2.5-turbo with a temperature of 0. The choice of temperature 0 ensures determinism in our model, preventing it from getting sidetracked and maintaining a focused and consistent generation.

Now, we are going to use different techniques to make it precise for our downstream task i.e. Sentiment analysis. There are lots of different ways to do it:

1) Prompt Engineering:

Prompt engineering is a growing field that involves designing and optimizing prompts to maximize the performance of large language models like GPT. As these models advance, the way we prompt them becomes increasingly important. Recent research shows that well-crafted prompts can significantly improve reliability and enable models to tackle more complex tasks than previously believed.

Following are some prompt engineering techniques that are commonly used:

  1. Zero-shot prompting: This method enables large language models (LLMs) to handle new tasks even without prior examples or understanding of the task. It operates through a technique called ‘prompting,’ where you simply give the LLM a natural language description of the desired task.

  2. Few-shot prompting: While large-language models demonstrate remarkable zero-shot capabilities, they still fall short on more complex tasks when using the zero-shot setting. Few-shot prompting can be used as a technique to enable in-context learning where we provide demonstrations in the prompt to steer the model to better performance. The demonstrations serve as conditioning for subsequent examples where we would like the model to generate a response.

  3. Chain of Thought Prompting: Chain of thought prompting is a helpful technique for AI systems to simplify complex tasks by breaking them down into manageable steps. Instead of tackling a challenging problem in one go, this method promotes explaining the reasoning process by breaking the solution into a series of smaller, incremental steps. It begins by clearly defining the end goal and then considers the logical prerequisites and sub-tasks required to reach that goal.

2) Fine-tuning

Fine-tuning is a useful process that lets users tailor pre-trained language models (LLMs) for specific tasks. By fine-tuning a model on a small dataset containing task-specific data, you can enhance its performance for that particular task while keeping its overall language understanding intact.

The two main Fine-tuning Methods are as follows:

  1. Full instruction fine-tuning: Full instruction fine-tuning is a technique used to adapt Large Language Models (LLMs) to specific tasks. The process involves adjusting all parameters of the LLM using task-specific data. This adaptation allows the model to perform more effectively on specific tasks, potentially leading to improved performance. The need for full instruction fine-tuning arises because even the most powerful pre-trained LLM might not always meet specific needs right out of the box. For instance, an application might require a unique structure or style, or the pre-trained LLM might lack knowledge about specific documents crucial to the application. Furthermore, certain domains, industries, and even particular enterprises often have unique terminologies, concepts, and structures not prominently represented in the general pretraining data. Therefore, full instruction fine-tuning is a valuable method for tailoring LLMs to more specific use cases.

  2. Parameter-efficient fine-tuning: Parameter-efficient fine-tuning (PEFT) is a technique used to adapt large pre-trained models to various downstream applications without fine-tuning all of a model’s parameters. This is because fine-tuning all parameters can be prohibitively costly. Instead, PEFT methods only fine-tune a small number of (extra) model parameters. This significantly decreases computational and storage costs while yielding performance comparable to a fully fine-tuned model. PEFT addresses issues such as the infeasibility of full fine-tuning on consumer hardware and the high cost of storing and deploying fine-tuned models independently for each downstream task. It also overcomes the problem of catastrophic forgetting, a behavior observed during the full fine-tuning of Large Language Models (LLMs).

In this instance, we will leverage prompt engineering techniques, utilizing the Langchain template functionality, to construct an optimized prompt for conducting sentiment analysis in the stock market. The objective is to create a prompt that not only provides sentiment Analysis but also offers explanations for the model’s inferences.

template = """
Identify the sentiment towards the Apple(AAPL) stocks from the news article , where the sentiment score should be from -10 to +10 where -10 being the most negative and +10 being the most positve , and 0 being neutral

Also give the proper explanation for your answers and how would it effect the prices of different stocks

Article : {statement}

# forming prompt using Langchain PromptTemplate functionality
prompt = PromptTemplate(template = template, input_variables = ["statement"])
llm_chain = LLMChain(prompt = prompt, llm = llm)

Now that we’ve established the LLM chain, let me give you an example of its inference.

Running the LLM chain :


The output would look like this:

AAPL sentiment prediction by the model


Now to to analyze the market condition of AAPL (Apple) stocks let’s analyze 100 articles and draw some conclusions.

So, first, we have to make sure we don’t cross the token limit of our model, which is 4097 for me. So we will filter out articles with a number of tokes < 3500:

# A function to count the number of tokens
def count_tokens(text):
    tokens = text.split()  
    return len(tokens)

Counting tokes for all the rows in a dataframe:

# Applying the tokenization function to the DataFrame columndf['TokenCount'] = df['content'].apply(count_tokens)

Filtering the data frame according to TokenCount:

# Define a token count threshold (for example, keep rows with more than 2 tokens)
token_count_threshold = 3500

# Create a new DataFrame by filtering based on the token count
new_df = df[df['TokenCount'] < token_count_threshold]

# Drop the 'TokenCount' column from the new DataFrame if you don't need it
new_df = new_df.drop('TokenCount', axis = 1)

# Resetting the index
new_df = new_df.reset_index(drop = True)

Now, this time I would change my prompt template so that I would get a concise output:

template_2 = """
Identify the sentiment towards the Apple(AAPL) stocks of the news article from -10 to +10 where -10 being the most negative and +10 being the most positve , and 0 being neutral


Article : {statement}

# forming prompt using Langchain PromptTemplate functionality
prompt_2 = PromptTemplate(template = template_2, input_variables = ["statement"])

Let’s form the new LLM chain:

llm_chain_2 = LLMChain(prompt = prompt_2, llm = llm)

Let me demonstrate one inference here:

print('News sentiment: ',['content'][2]))

Updated model’s sentiment prediction

Great, we are now able to get a concise output. Now, we are going to create a for-loop to iterate through the data and get the sentiment of each news:

x = []
for i in range(0,new_df.shape[0]):


Now let’s form some pie charts to see the market sentiment of AAPL stocks:

import matplotlib.pyplot as plt

dt = pd.DataFrame(x) # Converting into Dataframe
column_name = 0 # this is my column name you should change it according to your data
value_counts = dt[column_name].value_counts()

# Plotting the pie chart
plt.pie(value_counts, labels = value_counts.index, autopct = '%1.1f%%', startangle = 140)
plt.title(f'Pie Chart')
plt.axis('equal')  # Equal aspect ratio ensures that the pie is drawn as a circle.

# Show the pie chart

AAPL market sentiment

The pie chart indicates that a significant number of articles were neutral. However, to ensure accuracy, we should filter our data and focus on analyzing only the non-neutral information.

Removing neutral values:

value_to_remove = '0'
# Remove all rows where the specified value occurs in the column
dt_new = dt[dt[0] != value_to_remove]

Visualizing the new data:

value_counts = dt_new[column_name].value_counts()

# Plotting the pie chart
plt.pie(value_counts, labels = value_counts.index, autopct = '%1.1f%%', startangle = 140)
plt.title(f'Pie Chart')
plt.axis('equal')  # Equal aspect ratio ensures that the pie is drawn as a circle.

# Show the pie chart

AAPL market sentiment, excluding neutral values

Observing the trends, the combination of +5 and +7 contributes to nearly 40% of the data. Factoring in additional values like +10, +8, and +3, the cumulative percentage of positive articles rises to 52.5%. This pattern indicates a prevailing optimistic sentiment, implying a favorable perception of Apple Inc. in recent articles. The positive outlook identified may have potential implications for shaping overall sentiments regarding Apple’s market performance.


In our study, we employed the Stock Market Financial News API provided by EODHD to collect stock market news articles and utilized OpenAI’s sentiment analysis model to assess the sentiments conveyed in these articles.

To ensure seamless compatibility between our data and the OpenAI model, LangChain, a language processing tool, was utilized. To refine the inputs for the OpenAI model and improve the accuracy of our sentiment analysis, we implemented prompt engineering techniques. We conducted sentiment analysis on 100 articles to gauge the current market sentiment surrounding APPL stocks.

This holistic methodology enabled us to extract meaningful insights into market trends based on the sentiments expressed in the news. With that being said, you’ve reached the end of the article. Hope you learned something new and useful today. Thank you very much for your time.


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