Sure, this suggestion is for all investors, not only for newbies. We must always remember that we must invest with a safe allocation. If we try to invest with excessive funds, it probably brings bad impacts to our financial stability. Also, it may bring a mental pressure because the volatility of Bitcoin price. We must know Bitcoin may experience big corrections or sideways, it doesn't always increase all the time. Investing with excessive funds can make a stressful condition whenever Bitcoin is in red market.
This principle is vital, hence, applicable for everyone. If any investor starts with betting in dangerous style by borrowing money for investment, don't expect that with bad risk management at start, the journey will be smooth enough for avoiding nightmare (loan expiration call, market liquidation) in future.
Capital is capital, and if you fail in defending it, you lose it and have no capital for doing anything else later. Small or big investors, this principle works for every investor. It is more dangerous in Bitcoin market with its high volatility and no circuit break like stock market.
Having proper knowledge is surely the first thing that we must ensure before we start Bitcoin investment. It is true that there is no guarantee to take profits in Bitcoin. It is possible to get a lose if we don't know when the right time for entry and exit. Having proper knowledge will ensure us to have good analysis. So, it won't be difficult to determine the right time both for entry and exit.
Actually, it is not a must to hold for a long time. We can hold for few weeks or few months, depending on how much profits to expect. However, we must hold for few years if we want to get maximum profits.
Having proper knowledge starts with what you know accurately about the market volatility, and how exchanges give you loan position and how they need in your collateral as well as most importantly how they liquidate your collateral in volatile market times and when your positions are in severe loss.