What Is the Relationship between a Coin’s Market Capitalization and Its Security Cost?

There is a strong, though not direct, correlation between a coin's market capitalization and its security cost. A higher market cap generally implies a higher economic value being secured, which attracts more legitimate miners, leading to a higher total hashrate.

This high hashrate increases the cost of a 51 percent attack, as the attacker must spend more to acquire the necessary mining power. Therefore, higher market cap coins tend to be more secure due to a higher economic barrier to attack.