None of these things are monolithic, and none of them mean what you're suggesting they mean.

- Stocks are percentage ownership in a business. They are not valued at their fundamental worth, they are valued at whatever someone is paying for them. The best time to buy a stock is when you know it will be worth more in the future than it is now. Unfortunately, if you know that you're forbidden from trading that stock by the SEC. Insider trading rules are different worldwide; you might be permitted to trade in Germany, for example.

- Pensions are fixed-payment annuities whereby you contribute during your career in order to be eligible to receive a stipend as part of your agreement. The investments backing pensions are effectively opaque to its participants; their only involvement is putting money in and taking money out. Those managing the pension invest in a number of ways; when you hear the phrase "institutional investors" the investors being described can be pension funds.

- a 401(k) is a specific type of retirement fund ( that was invented by mistake, by the way) that is cheaper and much easier to manage than a pension. With a pension, your employer is responsible for you having enough money when you retire. With a 401(k), you are.

401(k)s and pension funds can both contain stocks. 401(k)s can also contain CDs, mutual funds and ETFs (exchange-traded funds - basically a mutual fund governed by algorithm rather than fund manager). Pension funds can contain land holdings, bonds, all sorts of stuff that non-institutional investors can't touch. If a mutual fund or ETF invests heavily in something that is denominated in foreign currency, and that foreign currency suddenly rises, that ETF will also increase in value... unless the stocks that make up that ETF rely heavily on trade in which case see above.

But that's just the beginning of the confusion. You may have heard the term "arbitrage." Arbitrage is the act of exploiting market inefficiencies between exchanges or commodities such that you make a gain without any trade taking place. For a while there was a way to make money by buying shares of Shell Oil on the FTSE (where it is publicly traded) and then selling shares of Shell Oil on the Deutsche boerse (where it was also traded) because Shell had a clause that allowed the holder to exchange one for the other. No value was created or destroyed but large firms capable of buying and selling tens of millions of dollars worth of stock could make tens of thousands of dollars a day by moving counters around on the monopoly board. Note that this took exchange rates into account - it was purely leveraging the inefficiencies of buying in one place and selling in another (the loophole has since been closed). But hopefully it serves to demonstrate that this shit really is complicated and that there are people who spend a lot of time wringing every last dollar out of it.

This is one reason why I really don't like playing with cryptocurrency - the efficient-market hypothesis suggests that items being traded are priced with everyone knowing everything there is to know about the underlying values and if you don't know why something is rising or falling, it's because you're in the dark, not because everyone else is wrong. But you look at something like Bitcoin where fewer than 200,000 people in the entire world own any and some unknown quantity of it is in the possession of Chinese Tongs and where the world's largest holders are anonymous and the efficient market hypothesis is a joke. And then you look at number 2 Ethereum and it's a quarter of that and some chucklefuck like me, who bought in at 70 cents, can splash around big trades that spook people and move the market because there are so few players and so much inflated value. And then you look at number 3 ripple and the market share is a tenth that of Ethereum and those guys might as well be trading marbles except they never have to own any so they can have a virtual warehouse full of aggies and cateyes and trade them back and forth every twenty minutes if they wanted.

And then you recognize that the small-scale problems the crypto world has are exactly the large-scale problems the bond world has because it's all dark pools, there's no transparency and things are all fun and games until the music stops and suddenly Bear Stearns is gone.

And I recognize that this does not directly answer your question, but I hope it illustrates that your question can't really be answered, and that the questions that can be answered are not only a lot harder, they're a lot less useful to answer. This shit is complicated, unpredictable and entirely unfair and it's one of those things where the more you study it, the less you think you understand.