Musk once did the math: the most expensive investment is time. This statement is quantifiable. He actually did the calculations, and in great detail. Money lost can be earned back. Time cannot. He calculated how long this money can sustain a company. Most people focus on returns, a few manage risk, and very few seriously calculate costs. These three things have completely different outcomes over time. 01 Costs Returns increase, costs increase, only risk diminishes. Musk has a rather counterintuitive observation: as returns snowball, costs accumulate, while risk diminishes. Costs are the easiest to overlook. The larger the account, the more frequent the turnover, and the greater the friction. There are bid-ask spreads, transaction commissions, fund fees, and that most easily forgotten tax. In the US stock market, holding for a full year before selling incurs a maximum federal long-term capital gains tax of 20%. Holding for less than a year, it's treated as ordinary income, with a maximum tax of 37%. The same amount of money can result in significantly different taxes depending on how many months you hold it. Therefore, people who frequently trade may appear diligent on paper, but they are actually working for the cost of capital. Compound interest is gradually eroded by these small details. 02. Commitment Only those willing to spend time committing have the right to talk about compound interest. Musk's 2008 deal is the most blatant example. That December, Tesla's cash reserves wouldn't last a week. The board approved $40 million in convertible bonds, but just before signing, an existing shareholder suddenly withdrew. Musk himself stepped in $12 million to cover the shortfall. At that time, he only had two choices: either let Tesla die that winter, or invest more money. By then, he had invested over $70 million in Tesla and another $100 million in SpaceX. His readily available cash was almost depleted. The deal was completed in the last few hours of Christmas Eve. He later said that if it had been a day later, the salaries wouldn't have been paid. SpaceX's first three launches all failed, only succeeding on the fourth. By December 23rd, NASA's $1.6 billion contract was finalized, and both companies had finally pulled back from the brink. At that time, almost no one on Wall Street was optimistic about Tesla. No one was willing to invest in a car company that wasn't profitable, couldn't ramp up production, and had no cash on hand. Car manufacturing is a capital-intensive business. Without investing money in production lines and the supply chain, it's impossible to tell whether a product will even be viable. On June 29, 2010, Tesla went public on Nasdaq with an offering price of $17. By the closing price on November 10th, it was $379.78. Including the two stock splits in 2020 and 2022, $1,000 back then is worth approximately $335,000 today. Time doesn't speak for anyone; it simply separates those who dare to bet big from those who are unwilling to. 03 Honesty The prerequisite for long-term holding is rational judgment and risk awareness. Holding onto a company long-term depends on whether your judgment of it can withstand bad news. Belief alone cannot sustain that long. Musk stumbled on this. On August 7, 2018, he tweeted that he was considering taking Tesla private at $420 per share, and that funding was already secured. The stock price rose more than 6% that day. The SEC later accused him of not discussing specific terms with any potential investors. The SEC subsequently sued him for securities fraud. The settlement resulted in him and Tesla each being fined $20 million, him stepping down as chairman for three years, and having to approve tweets before posting them. This tweet later became a negative example in American stock market textbooks. The market priced an unfounded statement at $40 million plus a title. Courage and honesty may sound abstract, but they are the most valuable qualities. Courage is the courage to hold on when others laugh at you. Honesty is the honesty to ensure you hold onto something genuine. Finally, standing with time relies on self-discipline. Even Elon Musk hasn't managed to never sell. From the end of 2021 to 2022, he sold approximately $39.4 billion worth of Tesla stock in several rounds, a large portion of which was to raise funds for the Twitter acquisition. So, don't treat "never sell" as a belief. The only true measure is your reason for selling: has the company changed, or are you short of money? The former is judgment. The latter is being forced. If you can't think of any company worth holding for ten years, it's probably just a bargaining chip, not an asset. The flow of water doesn't compete for speed, but for continuity. May you also find that company you're willing to stay with for a long time, letting time do the work for you.