@stillers - If you back out what has happened with the performance in MIGPX since the March 2020 downtown MGGPX has bested it over all time periods.

Well first, their TR performances are not all that different.
I see your point and understand why one might argue it.
But I disagree with the concept of creatively subtracting out any interim period or event in order to compare TR performances. The time periods and/or events happened and there's no going back on them. But wouldn't it be nice if we could?
IF you subscribe to that concept, why not let's for instance then take out any/all periods that MGGPX outperformed MIGPX, or any market events that more negatively impacted MGGPX?
IF you subscribe to that concept, note that MIGPX's TR YTD, past month and 3-months, interim time periods well after the March crash, are ALL DOUBLE that of MGGPX's. So the current allocations of MIGPX are still working doubly better than those of MGGPX.
IF you subscribe to that concept, do you also plan to subtract out all future interim periods or events that more negatively impacted MGGPX?
From another angle...Should an investor just ASSUME that eventually the effects of the March 2020 downturn will magically reverse at some point and MGGPX will get back to an outperformance period(s)? Feel free to do so, but my money is riding on MIGPX going forward.
Either way, they are both IMO great WS funds and it's likely they'll both continue to outperform others in their cat in future periods.
Not really looking for answers to those conceptual questions. Just noting that's my take on this concept that some investors like to sometimes apply to discussions about past performance. I trust it differs from yours and likely others, and I respect those opinions. But beyond what has been said about it so far, I'm not interested in a spitting contest over it so I likely won't comment further as I've got nothing more to add.
Other than this...Another reason for my preference of MIGPX over MGGPX going forward is its use since inception in Dec 2010 of the incredibly experienced 6-member management team that is still in place over MGGPX's use of a single (albeit outstanding) PM.

Edit to add: Mggpx is now closed to new investors now I believe however.

Despite this press release on MGGIX...
https://www.thinkadvisor.com/2020/09/04/morgan-stanley-to-close-global-opportunity-portfolio-to-new-investors-portfolio-products/
...it appears MGGIX/MGGPX, while showing CLOSED at VG, is still OPEN at Fido. To wit, I mocked up a Fido trade for MGGPX that was accepted. I cancelled the trade and am not sure if it would have executed. The article does state "...there will be a few exceptions" to the closing. Interested investors may want to inquire with MS or Fido about its availability. If it is CLOSED, that would make the decision between the two for new investors a simple one.

Can't really answer that question without more information regarding investment goals and financial situation. Is this money for retirement or to pay for college for instance? If it's for the former it should be invested aggressively, the latter conservatively as the child is 18 and will need the money right away. Is this 18 year old on his/her own and this is all the money he/she has or is it play money his/her parents can give him? The former should be conservative despite his/her age, the latter aggressive. Does this child have any debts he/she should pay off first? Just because someone is young is not a strong indication of how money is to be invested.

And an 18-yr old should learn to understand and embrace volatility as early as possible in their investing career. As one legendary M* poster used to routinely remind us, "Volatility is the price you pay for growth."
Note: MS also has some of the very best LC, MC and SC growth funds as I've posted elsewhere. MSEGX could easily be suggested for the OP also, but the noted WS or Total Mrkt Inx funds seem best. Hard to go too far wrong with any of those.
Aside: My mentor handed me Fido Magellan on a platter as my first fund for its glorious ride through most of the 80's. Then came Fido Low Priced Stock. They paved the way for early retirement, so this first fund choice can be very important over the long haul. Best wishes to the OP.

Yes. FPA and Queens Road merged several years ago. Steve Scruggs has been running the small cap fund since 2002. While value funds have been out of favor versus growth, this small cap value fund still managed to gain a modest 13%.
This is one way to diversified away from the FANNG stocks.

I prefer MIGPX over MGGPX, though both are great WS funds. MIGPX is much smaller and has shown consistently better TR performance over all periods despite higher ER and significantly higher turnover. That said, I would easily suggest either as an 18 yr old's first fund. Disclaimer: Heavy bias toward MS funds, among the best funds in several cats yet so under-appreciated.
By the book though, any of a number of low cost, Total Stock Market Index funds would be the suggestion.

From a January 16 discussion at MFO.

@msf makes good points and my take-away is that we as shareholders learn late in the game what a manager’s strategy might be (or was at a point in the past). Most MF prospecti give latitude to permit an active manager to shift back and forth between growth and value, or cash and fully invested, etc. It’s nice when a fund stays true to its advertised mandate, but I suspect purity suffers in the face of markets that refuse to follow some wonk’s thinking. Once I find a fund I like, I’m inclined to let management pick the stocks.
There are stocks and countries in EM indices that do defy pigeon-holing. When I lived in Seoul in 1980-1 the excavations for the subway line revealed that underground sewer pipes were nothing more than 55-gallon drums welded together. Korea really was emerging then. Today a visitor would be struck by the modernity of the city whereas the former resident might be trying to mentally resurrect the missing odor of sewage gas that once assaulted the nostrils in the capital. One steps off the plane in New Delhi, OTOH, and one smells an acrid smoke, a combination of industrial pollutants and the open fires burning in the streets to warm people and to cook their meals. Maybe Korea should not be in EM funds, but Taiwan is pretty modern, also.

What fund, ETF, or CEF would you recommend for an 18 year old who is new to investing?

SCG MSSMX UP 5.01% today.
Just sayin'.

And my thanks for bringing it to my attention the other day. I looked at it and bought immediately; which was, fortunately, BEFORE that surprising gain! I'm a believer in the SC rotation; so your mention was timely...

That

WAS a surprising move yesterday, but keep in mind that with its 30+ SD, these kinds of daily moves happen with this fund, well, pretty much daily. You don't get to a ~150% annual TR (2020) without 'em!

I've been holding ARKW and ARKG; believe me, I'm familiar with wild swings! 8^b

It's not always easy to gauge a fund's style from its sectors, or its countries for that matter. For example, while companies in the financial sector tend to be value investments, that doesn't make something like Robinhood's anticipated IPO a value play.
In any case, according to the FSEAX's latest monthly fact sheet (Dec 31), just 9.19% of the portfolio is in financials, down from 11.07% at the end of November. In comparison, technology accounts for about 1/3 of the fund.
Zhao says that he has "reduced some positions ... that have done well and added to those that are more exposed to the value side [i.e. those that have not done well]. ... it only makes sense to take some profits off the table and begin to plan what might come next."
That sounds more like rebalancing than a change it target weighting. The interview is dated Oct 31. M*'s factor analysis based on the fund's Nov 30th portfolio shows the fund to be more toward the growth side of the value/growth spectrum than in any time over the past five years, and also more growth focused than the category average.
Regarding countries: FSEAX counts the 12% of its portfolio in Korea as EM. Most index providers consider Korea a developed country. MSCI is the laggard, still calling Korea an EM country - because the won isn't traded 24 hours/day, not because its gross national income is too low or its stock market too small (they're not).
Some investors posit that separate international funds are not needed because so many domestic countries derive much of their revenue globally. By that reasoning, what are we to say about TSMC (6% of the fund)? Is it really an EM company? Based in Taiwan, it gets 60% of its revenue from the US.
None of this is meant to suggest that FSEAX isn't good at what it does. Rather it's to suggest taking a closer look at this, or any fund, to understand what it's really doing.

here is an interview with the fund manager of FSEAX where he describes how he is rotating to value for 2021. Financials are now the largest sector in his portfolio. https://fundresearch.fidelity.com/mutual-funds/analysis/315910851?documentType=QAA

@BenWP yes that caught my eye too in the fund. They're sector exposure is also very interesting with strong weightings in consumer cyclical, financials, and industrials. So it is more value oriented. I havent bought it yet but watching it. Another fund Im really intrigued by is MATFX. Pull it up on Morningstar and you'll see it scores in the top 10% for pretty much every period from 1 week through 5 years. Ive been following the manager for awhile now. Very sharp guy. This is a growth fund focused on disruption. At some point I'll buy one of these or add to FSEAX.

SCG MSSMX UP 5.01% today.
Just sayin'.

And my thanks for bringing it to my attention the other day. I looked at it and bought immediately; which was, fortunately, BEFORE that surprising gain! I'm a believer in the SC rotation; so your mention was timely...

That WAS a surprising move yesterday, but keep in mind that with its 30+ SD, these kinds of daily moves happen with this fund, well, pretty much daily. You don't get to a ~150% annual TR (2020) without 'em!

SCG MSSMX UP 5.01% today.
Just sayin'.

And my thanks for bringing it to my attention the other day. I looked at it and bought immediately; which was, fortunately, BEFORE that surprising gain! I'm a believer in the SC rotation; so your mention was timely...

Grantham ties a close at hand deadline to his bubble call and warns more generally about future inflation:

‘We will have a few weeks of extra money and a few weeks of putting your last, desperate chips into the game, and then an even more spectacular bust…When you have reached this level of obvious super-enthusiasm, the bubble has always, without exception, broken in the next few months, not a few years.
“If you think you live in a world where output doesn’t matter and you can just create paper, sooner or later you’re going to do the impossible, and that is bring back inflation,” Grantham warned.

https://pionline.com/investing/grantham-warns-biden-stimulus-further-inflating-epic-bubble
https://marketwatch.com/story/stock-market-legend-sees-few-weeks-of-putting-your-last-desperate-chips-into-the-gamethen-pop-11611347617?siteid=yhoof2

Let's not forget the 400 lights service at Lincoln Memorial. And the pandemic rages on.
https://npr.org/sections/coronavirus-live-updates/2021/01/19/958449203/400-lights-for-400-000-dead-to-illuminate-lincoln-memorial-reflecting-pool

True, that.

SCG MSSMX UP 5.01% today.
Just sayin'.

Morningstar says the "payout ratio" is 135.75% (i.e. that ATT is not earning its dividend).
Value Line says "all dividends to net profit" is 63% (i.e. that the dividend is quite well covered by earnings.)
Am I interpreting these numbers incorrectly, or are they simply in conflict ?

YMMV = your mileage may vary.
Also, you can get the standard amount of SC exposure (floats between ~6%-~10%) through the use of a Total Market Index fund. VTSAX, e.g., currently had about 8% SC.
FWIW...Reasonably sure the rotation from LCG to SCG will continue for some time. SCs showing impressive resiliency during today's market action. That, and about $10, gets you a Starbucks.
EDIT: With 1/2 hour to go, SCs are asking investors, "When are you finally going to believe this rotation is real?"

There are 14 NTF Wasatch funds OPEN at Fido.