The fundamental theory I rely on is what supports me to make this trade (considering large positions when going all in).

1. Collect news every day, summarizing the positive and negative aspects. Certain news can have long-term benefits for specific coins, for example, the ETF for LTC and HBAR is going to be on the agenda, so I can choose to make a 2x long position when the price is low.
2. Based on the K-line trends, the K-lines of mainstream coins are traceable and align with price behavior, unlike altcoins that can fluctuate by 10% in just a few minutes.
3. Based on market sentiment, judge the direction to take in the coming week according to future and recent news. For example, if it is determined to go long this week, then only go long in the coming week. Alternatively, if the market experiences significant negative news, such as a decrease in expectations for interest rate cuts last year or Trump raising interest rates, then only go short.
In most cases, when the market is inactive and there is no liquidity, I choose not to trade. Those who can't wait should make their own judgment...