How stock prices are determined

Have you ever wondered why stock prices fluctuate so frequently? One moment, a stock is soaring, and the next, it's plummeting. These price movements are not random; they are driven by a complex interplay of market forces, economic indicators, and investor sentiment. For long-term investors and traders, understanding what influences stock prices is essential for making informed investment decisions.

Stock market indices like the Nifty and Sensex reflect these price trends, offering a snapshot of market performance. But what really causes these daily changes, and how can investors make sense of them? This article delves into the fundamental and technical aspects that drive stock price movements.

What is the basic principle behind stock price movements?

At its core, stock prices are governed by the simple principle of supply and demand. Here's how it works:

• High demand, low supply: When more investors want to buy a stock than sell it, the price goes up.
  
• Low demand, high supply: When more investors are selling a stock than buying it, the price falls.

Additionally, the type of orders placed in the market - market orders and limit orders - can influence price setting. Market orders are executed immediately at the current price, while limit orders set a specific price at which the stock should be bought or sold. The interaction of these orders contributes to the continuous price changes seen in the stock market.

Suggested read: My favourite stock is down 30%. Here's why I'm buying more

What key factors affect stock prices?

While supply and demand are the foundational drivers, several other factors influence stock prices. These can be categorised into microeconomic, macroeconomic, sector-specific, sentiment-driven, and global factors.

Company-specific factors (microeconomic factors)

• Earnings reports & financial performance: Revenue growth, rising profit margins, and increasing earnings per share (EPS) are critical indicators of strengthening fundamentals. Such results can boost investor confidence, driving share prices higher.
  
• Dividend announcements: When companies announce dividends, many investors try to buy the stock before the ex-dividend date. This can drive up the share price dramatically.
  
• Management changes: A new CEO or leadership team can influence how the market perceives a company's future prospects. However, only time will tell whether the share price will appreciate under the new leadership. That said, if the change is received well by investors, then it can fuel demand for the stock - this drives share prices up.
  
• Mergers & acquisitions: Expansion plans often increase confidence in a company's future, resulting in price gains.
  
• Stock buybacks: When companies repurchase their shares, it reduces the number of free float shares. This results in a smaller supply of shares, thus driving up the stock price.

Suggested read: Do share buybacks zoom share prices?

Market and economic factors (macroeconomic factors)

• Economic growth & GDP trends: A growing economy creates a favourable environment for companies to grow. This boosts investor confidence, and more people invest - this can elevate stock prices.
  
• Inflation and interest rates: Higher interest rates can make borrowing costlier for businesses, thus, eating into their profits. As a result, investors are less willing to take on risk through stock investing.
  
• Unemployment & consumer spending: A robust job market boosts consumer spending, positively affecting company revenues.
  
• Government policies & regulations: Tax incentives, corporate regulations, and fiscal policies can influence company earnings. If the government focuses on business-friendly policies, it can drive up the share price as investors become more confident in stock investing.
  
• Currency exchange rates: For companies reliant on exports or imports, fluctuations in currency rates can directly impact profitability and stock prices. A weaker rupee impacts import-heavy companies, while exporters benefit from this situation.

C. Industry and sector-specific factors

• Sectoral trends: Trends like rising oil prices may benefit energy companies but harm transportation sectors like airlines.
  
• Technological innovations: Changes in an industry due to evolving technology can lead to dwindling confidence in older businesses.
  
• Raw material prices & supply chain issues: Increased production costs due to higher raw material prices can reduce profit margins and impact stock prices.

D. Investor sentiment & market speculation

• News & media influence: Positive news can attract buyers, while negative news can trigger selling.
  
• Analyst ratings & recommendations: Ratings from brokerage firms can significantly sway investor decisions. If there's a downgrading in a company's rating, it can signal to investors that there is an underlying issue - selling becomes common after such an occurrence.
  
• Fear and greed index: This index measures market psychology. Usually, skyrocketing stock prices signal high greed levels. And the converse is often true for high fear levels.
  
• Panic selling & herd mentality: Emotional reactions to market conditions often lead to price volatility.

E. Global events & external factors

• Geopolitical events & wars: Conflicts and political instability can disrupt markets and impact stock prices globally.
  
• Pandemics & natural disasters: Events like pandemics can slow down economies and affect global trade.
  
• Foreign and domestic institutional investments: Large-scale buying or selling by institutional investors like FIIs and DIIs can significantly influence stock prices. That's why fund houses often are careful about investing in smaller companies. As large investments or sell-offs can lead to fluctuations in their prices.

Suggested read: A long, hard road | Stick to the basics

How do stock market indices influence stock prices?

Stock market indices constitute various stocks. Any underlying movement in those stocks also affects the indices. However, movements in these indices also affect stocks that are not included in the index since investors take the movement in an index as a sign.

How do investors predict stock prices?

Investors and traders use two primary methods to predict stock price movements: fundamental analysis and technical analysis.

Fundamental analysis

This method involves evaluating a company's intrinsic value by examining:

• Price-to-earnings (P/E) ratio: Indicates how much investors are willing to pay per rupee of earnings.
  
• Price-to-book (P/B) ratio: Compares the market value of a stock to its book value.
  
• Return on equity (ROE) & return on assets (ROA): These are known as return ratios and help determine how efficiently capital is utilised in a company.
  
• Debt-to-equity ratio: Evaluates how much leverage a company has taken on to finance its operations.

Long-term investors often rely on these metrics to decide whether a stock is undervalued or overvalued.

Suggested read: Fundamental investing in 3 steps

Technical analysis

This involves studying price charts and using indicators to predict future price movements. Key tools include:

• Moving averages (SMA, EMA): Helps evaluate price trends over time.
  
• Relative strength index (RSI): Measures the magnitude of price changes to offer an assessment of whether a stock is overbought or oversold.
  
• Support & resistance levels: Identify price levels at which it is optimal to buy or sell.
  
• Candlestick patterns: Visual cues that help predict future price movements.

Technical analysis is commonly used by short-term traders to identify buying or selling opportunities.

Suggested read: When technical analysis fails

Why do stock prices fluctuate every second?

Stock prices change every second due to the fundamental concept of supply and demand in financial markets. Here's how the factors you mentioned play into this:

• Market Orders (Immediate Buying or Selling)
• Every time an investor places a market order (an order to buy or sell at the current price), it interacts with the existing order book (a list of all buy and sell offers).
• If there's high demand (more buyers than sellers), prices tend to rise. If there's more supply (more sellers than buyers), prices fall.
• For instance, if many people suddenly place buy orders for a stock, the available sell orders at lower prices get filled, pushing the price higher to the next available level.
• High-Frequency Trading (HFT)
• HFT algorithms continuously scan the market for tiny price differences and execute trades within milliseconds.
• These algorithms can react to minute changes in market data, quickly buying or selling large volumes, which contributes to rapid price movements.
• Even small trades by HFTs can shift prices because they affect the immediate balance of buy and sell orders.
• Global Market Impact
• Decisions by major global entities (like the U.S. Federal Reserve raising interest rates) influence investor expectations.
• For example, if the Fed raises rates, global investors might anticipate a stronger U.S. dollar and shift investments out of emerging markets like India. This triggers more sell orders, increasing supply and pushing stock prices down.
• Similarly, global economic news can lead to sudden shifts in demand or supply, causing prices to adjust almost instantly.

Suggested read: Are FIIs leaving India?

Common myths about stock price movements

Let us address some misconceptions about how share prices work.

• "Low-priced stocks are cheaper and better investments."
  A stock's price doesn't necessarily reflect its value. We had discussed the topic of fundamental analysis and how it helps analyse intrinsic value. Discovering how much a stock is really worth is difficult, and the share price is rarely a reflection of it. Mostly because investor sentiment plays into share price movements, whereas the intrinsic value is a reflection of a company's fundamentals.
• "Stocks always move in predictable patterns."
  While trends exist, markets are influenced by unpredictable events. So, always be wary of people who tell you that they know how much a stock is going to rise or fall the very next day.
• "A stock hitting an all-time high means it's overvalued."
  A high price can also indicate strong growth potential. Also, it might signal that investors are willing to pay a premium for the company.
• "Past performance guarantees future returns."
  Historical trends provide insights but don't ensure future outcomes. That's why yesterday's top performers can easily become tomorrow's losers.

Conclusion

Stock prices are influenced by a multitude of factors beyond just supply and demand. While daily fluctuations are normal, long-term investment success depends on understanding a company's fundamentals, staying updated with market trends, and using a balanced approach to analysis.

However, keep in mind that share price movements are inherently unpredictable. Rather than buying a company to chase its upward momentum, you should focus on fundamentals. Lastly, always ignore speculation on price movements, no matter the source.

Also read: The importance of value investing

This article was originally published on May 07, 2025.